'''Scuba diving''' is a sport in which you swim underwater for extended periods using special equipment. The word '''Scuba''' is actually an acronym for '''self-contained underwater breathing apparatus.''' Scuba diving is an excellent way to see some very beautiful sites: coral diving sites with their colourful sea life are the most famous but other scuba diving attractions include shipwrecks and caverns.

Scuba diving can also be a very relaxing sport and in many places it's very beginner friendly. Many dive sites are accessible (under the care of an instructor) after a short briefing and training dive. You can learn to dive far more quickly than you can learn snow sports, for example. It's also suitable for people with a number of physical disabilities. As long as you can use the breathing equipment and are able to successfully propel yourself underwater you may be able to dive.

Destinations

Diving is a major travel activity: dedicated divers plan entire dive holidays, and others may want to include dive sites in their itineraries. Major dive destinations include:

Africa

  • Tofo in southern Mozambique — nice coral but known more for its abundance of manta rays, reef sharks, whale sharks and humpback whales
  • South Africa has sites spread along its coast that are usually famous for sharks and large marine life
  • * Port Elizabeth
  • Djibouti, New Diving destination. Djibouti is a truly unique ecosystem where the mix of the Red Sea and the Indian Ocean means an abundance of marine life. Between the months of September - January Djibouti is home to resting migrating whale sharks. It is common to see many whale sharks including Juvenile's who stay within the safe confines of the Djibouti coast line. 7 Brothers Islands is also a huge attraction to Djibouti waters. Further north than the Devils Cauldron this reef system (7 islands covering a vast area) is breathtaking. Monumental drop offs with stunning soft corals carpeting the walls, schooling fish and big pelagic's can all be expected.
  • Asia

    Asia's best diving is concentrated in South-East Asia:

  • Boracay in the Philippines — the most popular place in the Philippines to become certified. Quality beginner diving as well as a few good intermediate dive sites.
  • Ko Tao in south eastern Thailand — great for beginners and almost certainly Asia's most popular place to get certified
  • Manado, Sulawesi, Indonesia — intermediate to advanced diving, with occasionally strong currents
  • Perhentian Islands, Redang Island and Pulau Tioman — home of sea turtles and many species of sharks on the east coast of Peninsular Malaysia. Great diving deals because of fierce competition. For a less touristy but equally good dive spot, try '''Pulau Dayang''', which can be reached by dive boat from Mersing
  • The Similan Islands in south western Thailand — Widely regarded as Thailand's best diving. 70 km due west of Phang Nga, best accessed via liveaboard or a lengthy boat ride from Khao Lak. The Krabi region (Ko Lanta, Ko Phi Phi, etc) nearby is similar and rather more accessible. See Diving in Thailand
  • Sipadan in Malaysian Borneo — reef diving on a wall that descends 600m into the ocean
  • There are a few spots elsewhere for the adventurous:

  • Maldives — crystal clear water with over a thousand coral islets to explore
  • Yaeyama Islands in Japan — manta rays, hammerheads and mysterious underwater ruins
  • See Scuba diving in Asia for more destinations and One month of Southeast Asian diving and culture for a possible trip.

    Oceania

  • Great Barrier Reef -- large tropical reef system, most operators do sheltered easy diving. The reef is a few hours' boat ride from most of Far North Queensland. However the area has been over used and is in danger of being damaged beyond recovery.
  • Vanuatu -- intermediate level wreck diving, including penetration, on the ''President Coolidge'', blue hole diving with excellent visibility.
  • Micronesia
  • * Palau
  • * Saipan
  • * Chuuk Lagoon -- wreck diving, including optional penetration, on a huge number of ship and aircraft wrecks from World War II's Operation Hailstorm.
  • Fiji
  • See also Scuba diving in Australia

    North America

  • Florida Keys
  • British Columbia, Canada -- Cold water diving among wrecks with large sea life.
  • California: Monterey, Channel Islands, Farallon Islands.
  • Mexico
  • *Cabo San Lucas — on the southern tip of the Baja Peninsula is a meeting point of reef and blue water fish. While the number of dive sites are limited the variety of species makes up for it as do the viewing of the sand falls.
  • *Cozumel — has excellent and very accessible diving making it one of the most popular diving destinations in the northern hemispheres. The area is well known for reef, wall and drift diving as well as for a lively top-side scene.
  • *YucatanCancun and Playa del Carmen are well known for cave diving in addition to advanced diving in the labrynth of fresh water cenotes.
  • South America

  • Galapagos Islands - Darwin and Wolf Islands offer the opportunity to see schools of dozens of hammerhead sharks, while whale sharks and other large sea creatures are also frequently sighted.
  • Colombia - Colombia has some of the cheapest diving in South America. A cheap place to learn it is Taganga. But the islands of Isla Gorgona, San Andres and Providencia have some really good diving.
  • A little known but excellent location for large pelagics (i.e hammerhead sharks, whale sharks etc.) is Colombia's Malpelo Island. It is accessible by live aboard only.
  • Brazil - Many places for diving: Fernando de Noronha marine park (Pernambuco state), famous for marine life but including shipwrecks; the many shipwrecks of Recife (capital of Pernambuco); Arvoredo marine park (Santa Catarina state); cavern diving at Bonito (Mato Grosso do Sul state); cavern and cave diving in mine at Mariana (visiting Mina da Passagem) (Minas Gerais state); Abrolhos marine park and Salvador (Bahia state); Parcel de Manoel Luis {Maranhao state); Fortaleza (Ceara state); Maceio e Paripueira (Alagoas state); Guarapari (Espirito Santo state); Arraial do Cabo, Paraty and Ilha Grande (Rio de Janeiro state); and Ubatuba and Laje de Santos (Sao Paulo state). There are also liveaboards at Northeastern region. To dive in public parks (like Fernando de Noronha) one must be certified by one of the agencies recognized by IBAMA (Instituto Brasileiro de Administracao do Meio Ambiente), a federal organ.
  • Central America and Caribbean

  • Aruba
  • Belize
  • Bonaire
  • Cayman Islands
  • Honduras
  • Saba — this small volcanic island is located south of Saint Martin and differs from other Caribbean islands as it features steep drop offs and submerged pinnacles that are virtually untouched.
  • Dominica [http://www.dominica.dm/site/diving.cfm] — located in the center of the Caribbean island archipelago, Dominica's dramatic landscape is as spectacular underwater as it is above. Dominica is one of the top dive destinations in the world, and has been rated in Scuba Diving Magazine #1 for Marine Life, #1 for Healthiest Marine Environment, #1 for Small Creatures, and #3 Dive Destination.
  • Europe

  • Sardinia — The cave sistem in Alghero, with cristal water and astonishing limestone cliffs, is one of the more important cave diving place in Mediterranean Sea. Red coral, lobsters, groupers.
  • Cyprus the wreck of the ''Zenobia'' off Larnaca is among the best and most easily accessed in Europe
  • Malta — stunning limestone formations, steep dropoffs and good visibility make this possibly the best diving spot in the Mediterranean
  • Sicily
  • Iceland — Diving in a crack between the continents in water as clear as it can get, being filtered by lava fields for decades.
  • Middle East

  • The Red Sea, particularly the Sinai Peninsula (Egypt) commonly known to host some of the most captivating dive sites in the world from wrecks to reefs.
  • * Dahab home to the infamous blue hole
  • * Sharm el-Sheikh
  • * Hurghada
  • Oman
  • * Muscat
  • * Daymaniyat
  • * Fahl Island
  • * Salalah — has sea kelp and coral ? an unusual combination of cold and warm sea organisms.
  • Saudi Arabia — famously difficult to visit, but hence very well-preserved, and now open to tourists who can book well in advance
  • * Farasan Islands
  • * Jeddah
  • * Yanbu
  • Learn

    You need to be taught diving by an experienced and qualified instructor: aside from the complexities of assembling the equipment, diving has a number of risks that you need to understand, and safety procedures which you need to learn. There are also some basic skills that it's useful to practise under a teacher: the major one is controlling your buoyancy so that you aren't alternately sinking and floating but instead can swim along without yoyoing.

    Precisely because of these safety concerns, you will need to be trained and certified in order to be '''insured''' for medical treatment you need after a dive.

    Beginner courses

    As a first-time diver, you will learn to dive in '''open water''' with '''no decompression'''. The term "open water" refers to dive sites from which you can swim straight up to the surface (not caverns, for example). "No decompression" diving is diving timed so that you do not have to ascend in stages and wait long periods of time at various depths to expel excess gas from your system, meaning that in an emergency you can go slowly but directly to the surface without an undue risk of decompression sickness.

    Open water certification

    Open water certification courses are '''complete''' beginner level diving courses: they assume no experience, but after passing the course you will be certified as being able to dive in open water with a similarly qualified buddy diver but without an instructor's company, at least in cases where conditions are similar to those in your course.

    Open water certification is close to mandatory: many insurance companies demand either that you dive with an instructor or that you dive with open water certification in order to insure you and many dive tours will require that you are certified to at least this level.

    Open water courses tend to take three or four days full-time although you can often arrange to do them part-time or in pieces over a period of time. The time is divided between: time in a classroom learning the theory of diving; time in a pool learning how to use the equipment and move around underwater; and several dives in open water under the care of your instructor. Some certification agencies now offer the classroom syllabus online, and you only need to do the pool and open water dives with an instructor. Certification tends to be progressive: you need to pass each module in order to proceed to the next. It's usually the case that you pay for the course, not the certification: paying the money does not guarantee that you will pass the course. That said, beginner courses are not very challenging and, barring medical or psychological issues, nearly all participants pass.

    Some people recommend that you do the open water certification before a holiday rather than during it: you will need to be prepared to spend holiday time for time in a classroom otherwise. But many travellers do do their open water certification on holiday, either because they didn't plan to start diving until they arrived, they don't live near dive sites, or they have a particular location in mind where they want to spend their first dives. It is also usually possible to do a '''open water referral''' where you do classroom and pool training with one instructor and then do the required open water dives and finish your certification with another. This can be used to do the preparatory work at home and the dives on your holiday. You may need to do both halves of the course under the same certification agency's syllabus: check if your preferred agency is in the Universal Referral Program [http://www.universalreferral.com/].

    Other beginner courses

    If you only want to dive once or twice, or you want to try it before you commit to a full certification, there are often shorter courses (known as '''resort courses''') available. They are 'taster' courses in which you receive basic training in the equipment and do an open water dive under the supervision of an instructor. They are not complete certifications and do not fully train you to plan your own dives with a buddy; you will need the close attention of an instructor at all times. If you intend to dive more than a few times in your life, a full open water certification is worth the cost.

    These supervised dives and courses vary widely in quality and safety. You should check that you will be diving in a very small group (or ideally one-on-one with a certified instructor as your personal dive buddy); that you will be diving at a shallow depth (no more than 12 meters/40 feet); and that the conditions are as tranquil as the area permits: cold water and currents are more stressful to dive in than still warm water.

    Some certification agencies provide a syllabus for a resort-style course that will allow you to try an open water dive with a small amount of training and an instructor close by; for example PADI's "Discover Scuba" and "Scuba Diver" courses or SSI's "Try Scuba" and "Passport Diver" courses. These courses usually include part of the material for an open water certification, so that when you complete the short course you can go on to finish the open water course without needing to do the full course from the beginning.

    Some dive resorts offer their own supervised diving or resort courses. If your resort certification is only awarded by that resort and not by one of the certification agencies then you will not be able to use it at most other resorts and it is unlikely to count towards a full certification.

    Certification agencies

    There are a number of agencies which certify divers. They work by training and certifying instructors in their syllabus and teaching methods, and then allowing those instructors to certify individual divers. This section lists some of the certification agencies and their recreational (rather than professional or teaching) certifications. Your choice of certification will depend on a number of factors, primarily which certification agencies have a presence in the area you learn in, and in the areas you wish to dive in.

    All reputable dive shops will require '''certification''' of your skills in the form of a '''certification card''' ('''C-card''') from a recognized agency. This does not need to be the same agency that their own instructors work with: for example, a CMAS or SSI certified diver can dive with a shop that certifies under PADI.

    Recognised recreational certification agencies include:

  • The Professional Association of Diving Instructors [http://www.padi.com/] (PADI), the largest scuba certification agency, a commercial agency targeted towards recreational divers who want to learn quickly.
  • Scuba Schools International [http://www.divessi.com/] (SSI), another large commercial agency.
  • The National Association of Underwater Instructors [http://www.naui.org/] (NAUI), US-based, is the oldest recreational scuba certification agency.
  • The French-based Confederation Mondiale des Activites Subaquatiques [http://www.cmas2000.org/] (CMAS), a volunteer-run amateur organization that takes a more comprehensive approach than many of the commercial agencies.
  • The Professional Diving Instructors Corporation [http://www.pdic-intl.com/] (PDIC)
  • The International Diving Educators Association [http://www.idea-scubadiving.com/] (IDEA)
  • The American Canadian Underwater Certifications [http://www.acuc.es/] (ACUC)
  • The British Sub Aqua Club [http://www.bsac.com/] (BSAC)
  • The [http://www.isicert.com/ Independent Scuba Instructors (ISI)
  • Global Underwater Explorers [http://www.gue.com/] (GUE)
  • The Scuba Divers International/Technical Divers International [http://www.tdisdi.com/] (SDI/TDI), a certification agency designed to train with an emphasis on practical diving skills. SDI focuses on the recreational side of scuba diving and TDI is the mother branch that specializes in Technical Diving.
  • Advanced studies

    After completing a beginner level dive course, you can do additional courses to increase your '''skills''' or to pursue particular '''interests'''.

    Post-beginner skills involve learning to dive in new or more difficult conditions or learning to dive using different equipment. There are several reasons you might pursue more skills in addition to the simple challenge: increased safety knowledge or a desire to dive at particular sites that need those skills are among them. Often you will need to do a formal '''course''' in new dive skills because centers running dives using those skills will require evidence that you are properly trained. Post-beginner skills that usually require training include: diving using oxygen enriched air ("nitrox"), deeper diving (optionally including decompression), wreck diving and cave diving. A diving rescue course is worthwhile if you dive regularly, whether or not you continue as a no-compression open water diver. Most certification agencies have courses in these skills and some wrap a number of them up into various 'Advanced' certifications. Many divers proceed to more difficult conditions (cool water, diving at night) without formal courses, but they are available if you want them.

    Interests are particular reasons why you dive and include: underwater photography and videography; marine life identification; and marine life preservation. Many of the dive certification agencies have guided dives or courses in these fields but you may also be able to learn them informally from self-study, practise and fellow divers.

    Get in

    There are three major types of travelling to your dive site: liveaboards where you stay on the boat, day trips where you take a boat trip out to your dive site and back in the same day, and shore diving where you get in from the land.

    On a liveaboard

    Many divers prefer '''liveaboards''', where they sleep on the dive boat. This can save on accommodation costs, allow for more diving, and make it easy to get to know your fellow divers. Liveaboards range from 1 night in length to a fortnight or more. Liveaboards typically allow between 3 and 5 dives per day (depending on time and dive tables). The accommodation quality ranges from backpacker-esque, with 4-share cabins and showers shared between multiple cabins, to luxury cruise style accommodations. If you haven't opted for a luxury liveaboard, you will get your dives for about two thirds the cost of a day trip on a boat, even leaving aside any savings on accommodation.

    When travelling on a liveaboard:

  • pack as little as possible: a few changes of weather appropriate clothes, sleep gear, toiletries, light-weight entertainment (non-electronic is best) and your dive gear if you aren't renting
  • space is always at a premium, and it's easy to get things mixed up and annoy fellow divers, keep your dive gear together in a tub or bag on the deck
  • label your possessions with your name; they will be mixed up with a lot of similar looking equipment
  • dry off before heading into the interior of the boat so that the floors aren't constantly wet
  • most boats have a limited supply of fresh water for drinking and washing: have short showers
  • If you haven't spent much time on boats, you may not be aware of whether or not you get sea-sick. Some divers have an unhappy first dive trip on boats because they weren't aware that they suffer from sea-sickness. If you haven't been on a boat in open before, especially if you suffer from other kinds of motion sickness, you might be best off doing a few day trips on dive boats and experimenting with sea-sickness medication before committing to a liveaboard. That said, liveaboard trips for your first dives can be an excellent introduction, because you will usually do more than the bare minimum dives required for certification. Instead, you will get a lot of additional dive experience.

    The main activity on a liveaboard is the diving: you will wake early for your first briefing and only complete the last dive at or after sunset, day after day. During the surface time you need to let nitrogen out of your body you will usually be eating or sleeping. Liveaboard trips are excellent for dedicated divers, but may not suit divers who don't want to spend their entire holiday gearing up, diving, getting their gear off, eating and sleeping.

    On a day trip

    Many dive sites are accessible by a '''boat ride''' of a few minutes to a few hours from shore, so you can go out to the site on a boat, dive and return to your land-based accommodation at night. Boats which conduct day trips range from rubber dinghies equipped with an outboard motor to larger boats with indoor areas and hot showers. Longer day trips tend to entail nicer boats. Dive trips that take much of a day will usually include a catered lunch and perhaps some smaller snacks in the price. On a per-dive basis day trips are usually more expensive than liveaboards, so divers choose to day-trip when they want to only have a few dives at a particular set of sites, or when they want to alternate diving with other activities.

    As with liveaboards, some people take their first boat trip unaware of the possibility of sea-sickness. If you think you're at all likely to suffer (ie if you get sick in cars or other vehicles), you should take some preventative measures an hour before leaving on the boat.

    Be aware that not all day trip boats will have toilet facilities. Since it's not a good idea to dehydrate yourself before diving you may have to accept that you will have to urinate either over the side of the boat or into a bucket which you'll tip over the side and rinse. This can be a little more difficult for women to do quickly and safely. If this is unacceptable to you be sure to check on the boat's facilities in advance.

    Some day trips are organised by dedicated '''dive resorts''', which bundle day trips and land based accommodations into one price. You usually won't be compelled to stay with them in order to do their trips, but it may be cheaper. During peak times you may need to dive on most days of your stay to take advantage of the deal.

    From shore

    Shore-based dives are dives where the site is close enough to the water's edge that a diver can swim out into the water and descend to the dive site. Shore diving is cheaper than boat diving: unless you're paying an instructor or guide you only need to pay for any equipment you want to hire. You will often find a dive shop or dive resort conveniently located near a good shore dive site.

    Shore diving can be tiring if the site is not extremely close to the shore. Rescues may not be as fast as from a boat which will have spotters looking out for divers in distress. Be sure to check the length of the swim to your chosen site and its difficulty: shore dives are not necessarily easier than boat dives.

    Some shore dive sites are either only accessible, or are much safer and easier dives, at a certain tide height. Unlike on a boat dive, where the boat operator can time the visit to correspond to the right tide if need be, shore divers need to find out about tidal sites and tide times themselves. It's also not impossible to get sea-sick on a shore dive, particularly if swimming or resting on a choppy surface. It's easier to avoid though as most people find that dropping below the surface where there is less motion helps or removes the nausea.

    Do

    Different dive sites have different things to offer:

  • Many divers dive in order to see '''marine life'''. Particular favourites include '''turtles''' and especially '''sharks'''. The fascination with sharks can sometimes escape non-diving friends but most species of shark don't pose a threat to divers and they are beautiful to watch. Diving with a '''whale shark''' is one of the most highly prized diving experiences.
  • Divers interested in marine life or just in new experiences like to '''dive at night'''. Nocturnal marine life is different, and sometimes more active, than daytime marine life. Night diving does not require added equipment above daytime diving other than a powerful torch, and is often one of the first new experiences available to newly certified divers.
  • Tropical '''coral reef''' diving surrounds you with a sometimes unbelievable amount of colour and activity. Diving in tropical water is also comfortable and often low stress because the water is very clear. You are vulnerable to stings and to nasty coral scratches which are easily infected though: many divers choose to wear a full length thin wetsuit even if the water is warm enough to dive naked!
  • '''Wrecks''' have three appeals: fish life, historical interest and technical difficulty. Wrecks that have been sunk for some time become artificial reefs, attracting fish life and coral. The trade-off is that this tends to happen in warmer water, which will also cause the wreck to disintegrate more rapidly. Wrecks in colder water will attract less marine life but retain historical interest, particularly those of ships that were lost at sea rather than stripped of artefacts and scuttled. Wrecks of planes, particularly those shot down in wartime, are also popular. Divers can actually enter some wrecks: however this requires training and experience well beyond introductory open water training.
  • Many divers enjoy '''underwater photography'''. To take pictures while diving, you will need a waterproof housing for your camera. Many dive shops also have rentable cameras.
  • Buy

    Scuba diving equipment has standardised into a number of basic pieces, together with some optional pieces for certain conditions. Most dive centers will have all the standard equipment for rental, and as with many equipment-heavy sports it can be worthwhile to use rental equipment for a while before you decide to purchase your own.

    Standard equipment is:

  • An eye mask which includes a covering for the nose.
  • A snorkel (a short tube allowing you to breathe through it with your head underwater)
  • Fins for propelling yourself underwater
  • An exposure suit: a wetsuit for warm water or a dry suit for cooler water, perhaps with boots and gloves
  • A Buoyancy Control Device (BCD): an inflatable jacket allowing you to sink or float by deflating and inflating it
  • An air tank
  • A regulator: apparatus for delivering air from the tank to your mouth
  • A weight belt, weight harness or weight pouches integrated with the BCD
  • A depth gauge and Submersible Pressure Gauge (SPG), which shows the amount of air remaining in the tank
  • A timing device
  • Optional equipment includes:

  • A dive computer to calculate depth limits
  • Enriched air (extra oxygen) tanks
  • Underwater photography or videography devices. Disposable 'waterproof' cameras and cheaper underwater housings are generally only guaranteed to be leak free to about 3 meters/9 feet in depth, you will want one waterproof to ''at least'' 30 meters/100 feet. Properly rated housings are manufactured by many major camera manufacturers, and for more expensive cameras and video cameras housings are made by third parties.
  • Check the warranty conditions carefully, especially on expensive electronic equipment: water damage is usually not covered even on the housing warranties. Specialist '''dive insurance''' may provide insurance against loss of or damage to your equipment while diving, general travel insurance usually will not, even if it covers the medical aspects of diving.

    Rent or buy?

    The three pieces of equipment every diver should buy for themselves and bring along are '''fins''', '''snorkel''' and '''mask''': these need to fit to your body closely to be safe and comfortable, they're fairly cheap, and they don't need that much space. Up next is an '''exposure suit''' (wetsuit or drysuit), which is also better fitted than off the shelf, but is bulkier to carry along.

    But the bigger question for most divers is whether they should also make an investment in a full set of scuba gear, namely regulators, gauges and BCD. In purely financial terms, you have to dive quite a bit to '''save money''' this way, especially when you factor in yearly servicing fees. However, perhaps a bigger factor is '''safety''': not only can you ensure that your own gear is kept properly serviced, but you will already be familiar with the controls and performance of your own gear, which makes diving easier and increases the chances of you acting correctly in an emergency.

    The two items almost nobody brings along are tanks and weights, as these are extremely heavy and bulky, and practically always included in the dive price. For some destinations well and truly off the beaten track though (say, the Red Sea coast of Sudan) you may have to take along not just these, but the compressor too!

    Work

    The scuba diving industry in popular diving areas is always partly staffed by travellers, mostly divers themselves funding their diving.

    In order to actually be paid to dive in the recreational scuba industry, you will need to either be a certified '''divemaster''' or an '''instructor'''. Divemasters look after paying divers on the boat, handle any problems they have and tell them about the dive sites. They might also lead underwater guided tours of dive sites and assist in diving classes. Instructors run the diving classes themselves. You train as a divemaster first and then qualify for instructor training.

    Divemaster and instructor certifications are awarded by the same agencies that conduct Open Water courses. To enter the certifications you will generally need to be a skilled diver and have at the barest minimum somewhere in the order of 100 dives experience. Many master instructors recommend a great deal more experience before starting. Divemaster and instructor certifications are expensive to gain and expensive to keep, as you will need to renew them and also may have to pay an insurance premium.

    Other work available to travellers in the diving industry includes retail, boat operating and repairing, and cooking. If you're travelling out on dive boats you will often be expected to be able to dive, and possibly to hold diver rescue and first aid certifications, even if you're notionally the cook. For both diving and boat work, some experience in hospitality is valuable, although not always necessary.

    Almost all diving work, especially in extremely popular tropical diving locations, is badly paid. In some countries, divemasters are expected to work for tips alone. You will generally make enough to cover the basic expenses of a backpacker lifestyle and will usually get some free diving (although not as much as you expect).

    Stay safe

    The obvious safety concern with diving is that you must rely on your equipment to deliver you air. For this reason, scuba equipment is subject to rigorous testing according to various standards. Your part of ensuring your own safety is making sure that you are adequately trained and prepared for any dive you do.

    Being familiar with symptoms of equipment failure and recovery techniques obviously improves your safety. Your training will include information about performing basic safety checks on your equipment and about other guidelines. Further training is available in specialty courses.

    If you're diving regularly you will probably want to take courses in emergency diving procedures and in first aid including CPR.

    Basic safety precautions

    The basic precautions you should take for safe diving are:
  • Have an agreed '''plan''' for every dive, including where you expect to go, how you will manage your air supply and what you and others will do if something unexpected happens (common problems are getting low on air, getting lost or losing your buddy)
  • Do not dive '''alone''', always dive with a partner (a "buddy") who will stay close to you. Typically regulators have a second mouthpiece you can lend a buddy if they are out of air.
  • Do not dive in '''unfamiliar areas'''. Do some introductory dives or a dive orientation with a local instructor or experienced diver.
  • Do not dive '''outside your training and experience''', for example, diving deeper than you trained for, or diving in confined spaces when you're only certified for open water.
  • Do not dive when '''impaired''', e.g. by fatigue or alcohol.
  • If diving in a group led by a '''guide''', do not neglect your own planning and air management and if necessary plan to ascend early without the guide. Divemasters vary in skill, but even the best will not substitute for taking responsibility for yourself.
  • If you feel overly anxious about the dive, or feel you may not be fully qualified for the conditions, you have the absolute, unconditional right to '''end the dive''', no-questions-asked. Ultimately, you are responsible for deciding if any particular dive is right for you.
  • Seasickness medications

    Meclizine and dimenhydrinate (US brand name ''Dramamine'') are commonly used for prevention of seasickness, but both have the dangerous side effect of making you '''drowsy''', and the effect seems to be amplified underwater. Try them out before you dive, so you can judge your own reaction, and consider taking only half a dose. Alternatives include scopolamine patches (also known as hyoscine or "transderm scop"), which are very effective but often require a prescription; cinnarizine (Sturgeron), which is popular in Europe but poorly available elsewhere; and herbal remedies like ginger. You need to judge for yourself whether the illness is worse than the side effects: mild motion sickness may be managable, severe motion sickness can dehydrate and exhaust you.

    Respect

    Many dive sites are ecologically or historically sensitive areas. Dive tourism has the advantage of providing a reason to preserve many sensitive sites in order to keep the divers coming: for example, dive tourism may provide an incentive to control overfishing on divable reefs. However divers do themselves present a threat to many sites, having the potential to either directly damage them or subtly influence their characteristics. In order to help preserve dive sites:

  • '''Look but don't touch''', be it the bottom, coral, marine life or wrecks.
  • '''Don't take souvenirs''' as everything you take is one less thing for future divers to look at, and often one less home for sea creatures. This is also illegal in some areas in the case of both protected marine sanctuaries and wrecks.
  • '''Learn good buoyancy control''', so that you can avoid accidental damage to the site from crashing into things
  • '''Don't feed the fish''', as it alters their natural feeding patterns
  • Some dive organizations promote a diving variant of the leave no trace motto: "take nothing but photographs, leave nothing but bubbles."

    Stay healthy

    Health conditions which prevent diving

    Any medical condition which affects your respiratory or cardiovascular systems, or which may render you suddenly and unexpectedly unable to respond quickly or at all, might mean you cannot dive. Common contraindications are asthma, epilepsy, diabetes and heart disease. If you have any of these, or other illnesses which might cause similar problems, consult a doctor before diving. A physician with a knowledge of dive medicine and diver needs is best, particularly if you have a condition like asthma and want an informed opinion about whether your particular case means you can't dive.

    Most dive courses will require a detailed medical history from you or a doctor before you begin diving.

    Pressure related illnesses

    In scuba diving, air is delivered to your lungs at the surrounding water pressure. Breathing air at high pressure can cause a number of illnesses:

  • '''lung overexpansion''' in which high pressure air trapped in your lungs expands as you ascend, damaging your lungs and possibly forcing air into your bloodstream (an '''arterial gas embolism''')
  • '''decompression sickness''' ("the bends") in which dissolved nitrogen in your body forms gas bubbles as you ascend, blocking blood supply to limbs or organs
  • '''nitrogen narcosis''' in which nitrogen causes impairment similar to drunkenness
  • '''oxygen toxicity''' in which oxygen poisons your nervous system or lungs
  • All of these illnesses and their prevention will be discussed during diver training. Not all of them are fully preventable, hence you must be alert to the risk and know how to seek appropriate treatment. Always know how to contact the local emergency services and the diver emergency services (if they exist) before a dive.

    Preventing dive-related illness

    In addition to '''observing the time, depth and ascent rate limits''' you will be taught in training, there are some other things you can do to lower the chances of a pressure related illness. Before a dive trip and when diving , it is wise to:

  • Be '''well hydrated'''. Dehydration is not only a health concern in and of itself, but is also a contributing factor to many cases of decompression sickness.
  • Limit your '''alcohol intake''', partly because of its intoxicating effects and partly because it dehydrates you.
  • Avoid diving with '''blocked sinuses''' as high pressure air that enters them during the dive may not be able to exit, causing a painful "reverse block" that may take days to clear.
  • Avoid ascending to a '''higher altitude''' soon after diving; in particular, '''do not fly''' in most aircraft (commercial aircraft included) as they are rarely pressurised to sea level. Divers Alert Network (DAN) [http://www.dan.org] recommends [http://www.diversalertnetwork.org/medical/faq/faq.asp?faqid=54] waiting at least 12 hours after a single dive with no decompression stop before ascending, 18 hours after multiple dives without decompression stops, and more time again if there were decompression stops. Ascending sooner puts you at risk of decompression sickness.
  • There are several '''scuba emergency telephone hotlines''' set up in different areas of the world, many of which are provided by DAN [http://www.dan.org] , which can advise on your symptoms and sometimes organise rescues and treatment (however, you will still have to pay for both). Keep a note of your local hotline among your dive gear.

    Diving in high altitude lakes

    While diving at high altitude lakes, the risk for decompression sickness increases. Due to a lower barometric pressure in the environment, special dive tables should be used. These allow for the pressure difference correction factors and avoid decompression sickness.

    Preventing sea sickness

    A substantial number of boat divers will experience some '''sea sickness'''. You are probably more vulnerable if you experience other forms of motion sickness, eg getting sick in cars. Sea sickness, because of the many ways in which the boat can move, is usually more severe than car sickness. The upside, such as it is, is that as under the water is much calmer than the surface almost all sufferers find that their nausea vanishes within a few minutes of beginning to dive. If you are feeling ill but able to get your gear together, you should still be able to have a good dive.

    Sea sickness can be prevented for many people with the use of '''travel sickness prevention medication''' from pharmacists. See above for '''safety issues''' with sea-sickness medication. If your sea sickness is mild, you may be better off using natural remedies like '''ginger''' or simply staying near the centre of the boat, avoiding unnecessary motion, and looking at the horizon. However, severe nausea is extremely uncomfortable and vomiting will '''dehydrate''' you: if you suffer sea sickness this badly, or think you are likely to, you might find that the side effects are much easier to deal with than the nausea.

    If you are taking medication to prevent sea sickness, you should begin taking it well before you get on the boat so that it can be absorbed by the time the motion begins. Taking it an hour before boarding is effective; this will also give you some time to adjust to any drowsiness. Divers taking overnight trips sometimes begin taking medication the night before departure.

    A boat briefing will often include instructions on what to do if you think you're likely to vomit. If these aren't given and you forget to ask, the general etiquette is to go downwind (usually the rear of the boat) so that it doesn't blow into anyone's face, and to the opposite side to the ladder, and vomit overboard. Ask someone to accompany you so that they can make sure you're safe and won't fall overboard.

    Preventing injuries

    There are some injury risks that diving exposes you to. This is dependent on the site. For example, coral reef dives carry the risk of coral cuts, which can take months to heal well, and of stings and bites from venomous marine life. Educate yourself about risks in particular environments and particular sites and pay attention to dive orientations.

    You can dramatically reduce the risk of injury by exercising caution and not interfering with the state of the dive site (e.g. by provoking the marine life or disturbing the bottom). Assume that everything is dangerous (poisonous, sharp, aggressive, etc.) and you'll keep yourself out of harm's way by not being tempted to touch anything.

    Insurance

    It is very important to be '''insured''' for both general medical treatment needed for dive related illnesses and injuries, and in particular for decompression sickness treatment, which involves some hours in a '''recompression chamber'''. Recompression can be extremely expensive, around US$6000 an hour, and is specifically excluded by some insurance policies. In addition you should be insured for '''evacuation''', as evacuation from boats by the emergency services is typically conducted from the air and is also very expensive.

    There are many '''dive insurance policies''' which cover medical treatment needed after diving, including recompression. Some are associated with the certification agencies or with dive resort organisations. Typical prices are about US$500 per year for insurance for dives to less than 4 meters and US$1200 per year for coverage to any depth you have trained for. Less expensive group policies are also available from DAN [http://www.dan.org/insurance]. In addition dive resorts and dive tour operators will often have insurance for divers who are injured or become ill on dives they conduct.

    Many general '''travel insurance policies''' cover diving if you are certified or with an instructor, but check the terms first: some also exclude scuba diving.