Scuba

Hi Imbaai!

Buoyant force is an upward force exerted by a fluid, which opposes the weight of an object in the fluid. Objects immersed in water observes a loss in weight due to buoyant force.

Hope it is clear!

Cheers!!

The rate of respiration decreases in water due to atmospheric pressure (similar to when you climb up a mountain, you cannot breathe easily).

If you're wondering why the shape of the container is cylindrical, it's to keep the water pressure even around it so that it doesn't break nearly as easily as a square one, for example.

The aqualung was invented 1943. Prior to that scuba diving was done on rebreathers, but they were really only used by the military.
It was invented in 1942 and but they started selling the scuba gear for other people in 1943.
Scuba history from a diving bell developed by Guglielmo de Loreno in 1535 up to John Bennett's dive in the Philippines to amazing 308 meter in 2001 and much more... For more information please see lnks below for more information.

A blue and white flag (blue in swallow tail shape, is the letter "A".

It presently signifies "A scuba diver is down. Keep clear at low speed."

it used to mean "The boat is undergoing a speed trial."

There is no guarantee that you can prevent decompression sickness since everyone has an individual susceptibility to it. But there are things that can be done to lessen your chances and some are not well taught. One very big thing that can be done is to minimize your exertion both before during and after the dive. So when carrying your gear, do what you can to reduce your "work" and activity. Also, hydration is a big factor, so stay well hydrated. Of course, there are the obvious answers such as dive "conservative" by staying well within recognized time limits. Also, do safety stops. Safety stops can drastically reduce bubble formation and your risk of decompression sickness. I added 2 links that discuss this topic in more detail which include strategies to minimize decompression sickness.

Red because it has the shortest wavelength. Then you lose orange, green,blue, violet.

Free diving has several divisions for competition, each with its own record. The records can be found by using the link to our friends at Wikipedia and scrolling down.

A scuba regulator is designed to provide air to a diver via a demand valve system in a regulated and safe fashion.

A Scuba Regulator consists of two stages - a "first" and "second" stage. The first stage which attaches to a scuba tank by use of either a din or yoke valve, reduces the pressure of the air passing through it to an intermediate pressure slightly above the surrounding pressure at whatever depth of water the diver is at.

The part of the regulator that is in the divers mouth is called the second stage, and is a "demand valve" which gives air to the diver each time he inhales. On exhalation the valve closes and the exhaled air is released as bubbles from the exhaust ports built into the bottom of the second stage.

The fist stage of the regulator also has connections for a high pressure hose which is connected to a Pressure Gauge (showing the remaining air pressure in the scuba tank), one or two low pressure hoses to attach to the divers buoyancy control device and drysuit and an extra second stage which is used for emergency situations for use by another diver.

All regulators are designed with a fail-safe mechanism which means that if they suffer any technical problem, the regulator will "free flow" allowing the diver to return to the surface or to an alternate air supply safely.

Most wet suits are made of closed cell neoprene foam rubber faced with lycra on the inside and nylon on the outside. Dry suits may also be made with closed cell neoprene foam rubber but there are also suits made from solid plastic and rubber. A popular and rugged dry suit material is called Trilam because it consists of three layers, the outer layer being durable nylon. Dry suit seals are made of latex. The seals prevent water from running up your sleeves and down your neck.

Deep-sea diving act of descending into deep water, with some breathing apparatus, help them to remain there for an extended period. There can be multiple gases used depending on desired depth and length of dive the common is a tri-mixed gas of Nitrogen, Oxygen, and Helium.

Well, you can become a divemaster, but normally this does not pay well. You may be given food allowance or free accommoation and you get free dives. You may get commission from kit or courses you sell.

As an instructor, you earn commission on all courses you take, so teach more, earn more.

If you are an advanced instructor, you can teach more types of diving (wreck, deep, underwater photography etc), so you can teach more and earn more.

You can take this all the way to course director and even own your own dive business.

There's always commercial diving - this pays well but takes a lot of training and has a lot more risk attached.

You can be a rescue diver for police, fix pipelines for oil rigs, search sunken wrecks like wreck detectives....

There's plenty of different ways to earn money, depending on how much you want to put in.

As I heard once - to make a small profit in diving, you must start with a large profit!

I'm a PADI divemaster and I do it for the lifestyle, not the money.

Dive safe!

It is exactly like coke...

When the bottle is closed there are no bubbles because the pressure in the bottle is higher than the pressure outside the bottle. When you open the bottle you let the pressure out and now the coke is at the same pressure as the air around you. As a result the CO2 escapes the coke and you see bubbles.

Air is only a small part Oxygen. Air is mostly Nitrogen. When a diver goes underwater the nitrogen is pushed into his blood like the coke in the example. If he comes up too quickly then his blood acts like the coke in a freshly opened bottle and the nitrogen bubbles out.

Normal pressurized air is used for scuba diving. However, you can get mixed gases for SCUBA diving such as Nitrox, which is mixed gases of nitrogen and oxygen. This is used by deep sea diving, but it takes special training.

If your computer fails during a dive, end the dive immediately, perform as long a safety stop on 5 meters as your air allows and leave the water. Wait at least 24 hours before diving again.

If your computer fails during a dive, wait at least 24 hours before diving again. Do not simply switch to another computer if doing multiple dives, as the new computer won't know your nitrogen load from previous dives, but will assume that you are "fresh", i.e. have no nitrogen load.

If you're tech diving, the answer is simpler; you should always dive with a backup computer and a backup plan for ascent, written on a writing slate. If your computer fails, simply switch to your backup or go to your backup ascent plan.

Addition and Suggestions:

This is an involved answer and really depends on several factors including the depth you were at, how well you were monitoring your computer, if your computer has the pressure gauge built into it and if you were diving well with a buddy. If you were monitoring your computer well such as every few minutes and then noticed it failed, it is not this big crises many make it out to be. Obviously if your pressure gauge is built into your computer then your dives are over unless you have access to another pressure gauge. In this case, you do need to ascend, performs safety stops and exit the water.

If you were paying attention to your computer as you should during the dive, while it is uncomfortable not knowing your cylinder pressure you should know roughly how much you have left as well as knowing you do not breath much at shallow depths performing a safety stop, so you should still perform a safety stop while staying neutral so you can easily ascend if it starts becoming difficult to breath from your tank.

But if you still have access to your cylinder pressure, then you have many more options. One is to ascend to a shallow depth (with your buddy) and continue your dive. The key is being an educated diver that can make smart decisions. While each diver must have their own computer (as is taught in classes), if you have maintained very good buddy contact during your dive you and your buddy will have very similar nitrogen absorption and time limits. This may be a new concept to most, but take a minute to think about it as well as do some personal experiments. At the deep depths, the times are very short and do not change much at depth, so the difference in time between 120' and 130' is very small so a diver can fluctuate in depth some from their buddy and it will not have a drastic affect on their time limit. At the other extreme the times at the shallow depths are very long it is very hard to reach them. So the morale to this part of the story is you can use your buddy's computer as a guide if yours fails and if you ascend to a shallow depth after the failure (assuming you and your buddy were diving next to each other). Try this experiment. On your next dive compare your computer's "nitrogen pixels/graph" to your buddy's, the time your computer is showing you have left underwater as well as the time limits allowed on a repetitive dive. Assuming you have the same or similar computers that calculates the times the same, you and your buddy's computers will give you virtually the same information. Again this assumes you and your buddy were diving next to each other during the dive. Therefore if your computer fails, you may ascend to a shallow depth (where there is a lot of time allowed) if you and your buddy were diving next to each other during the dive and if your buddy's computer shows that you are well within your time limits.

So now the question becomes what do you do after the dive. Do you just dive with your buddy's computer again? Well this is a definite "no". The previous procedure was an "ending the dive procedure" and only allowed you to finish the dive at a shallow depth. You also have to assume your buddy's computer will fail on the next dive. So where does this leave you. Well you don't have to wait 12 or 24 hours before diving again. You can easily go to dive tables. Many think this is not possible when computer diving unless the kept very detailed information on their dive profiles. However it is actually very easy to do. Of course you still must have access to a depth gauge and timing device for your next dive. Using a dive table as a backup may be done in several ways. The simplest is to just assume the worst case scenario and assume you have a "Z" pressure group (or whatever is the greatest on your table) and then calculate your surface interval and allowed depths and times. But you will probably find that you knew the depths you were diving to and can calculate your previous dive(s) and find a repetitive pressure group designation. This is also a good reason to log your dive after every dive so if your computer fails in the middle of the day, you can look back at what your previous depths and times were. You may also use your buddy's computer to help with your table planning. Again, if you were diving in close proximity to each other your profiles will be very similar and if your buddy's computer gives an "average depth" you may use that for your dive table planning. By definition, the average depth is calculated over the entire portion of your previous dive and this large time sample should result in a very similar average depth for both of you. Also taking into consideration that this depth will need to be rounded up for dive table purposes (such as 36 feet to 40 feet) it is a very acceptable way to plan a dive. It must be noted that average depth only works if you did your dive profile from deep to shallow.

Many divers have been taught they must use their deepest depth during the dive for dive table purposes. But this is not correct as dive computers take nonstop recordings at exact depths. The reason divers are taught to use their deepest depth is because it is simple and they do not have a way to determine average depth without very detailed depth and time recordings or without a computer or device that will give them that information ... and if a diver is using a computer they often never consult a dive table. So if you have access to an average depth from your buddy's computer it is fine to use it for planning your next dive with a dive table (again assuming you and your buddy were next to each other during the entire dive). If you want to do another experiment, start logging your average depths during your dives and compare them to your buddy's. Not only will you find them to be very similar, but you will find that your average depth is actually pretty shallow and will probably be in the range of 35 to 40 feet even if the deepest portion of your dive was to 80 feet. This is simply because most divers spend a lot of time diving at shallow depths towards the end of their dive.

So in conclusion, perform proper buddy contact during your entire dive, monitor your pressure and depth during your entire dive, and ascend to the surface or a shallow depth using your buddy's computer as a reference if yours fails (spending time at a shallow depth towards the end of a dive in essence is a long safety stop that does you good) and then plan a repetitive dive with a dive table assuming you have a pressure gauge, depth gauge and timing device available.

You can scuba dive in several places. You can dive in the Caribbean, such as Jamaica, and the other islands. However, you have to be 16 to dive there at all. You can dive in several other places, but for more information you could ask a travel agent.

You can also Scuba dive at Manly beach(shelly Beach)

According to NAUI's dive tables: 25 Minutes

17 Meters for 23 minutes: Group E

30 Minutes at surface: Still Group E (Would need 55 minutes to go to D)

25 Minutes is your adjusted maximum dive time for up to 18 meters.

Wetsuits are typically made out of an insulating, rubber-like substance called neoprene and they are designed to fit snuggly (but not too tight). When a diver first jumps into the ocean, a small amount of water will seep in and form a layer of water between the diver's skin and the neoprene wetsuit. The diver's body will warm that water to nearly body-temperature. Because the wetsuit fits snuggly, that water does not circulate with the ocean water, it stays against the skin forming a warm insulating layer between the diver and the ocean.

It should be noted that wetsuits are not appropriate for diving in all climates as they will only keep a diver so warm. Another kind of suit called a Dry Suit is worn for dives in very cold water, and these suits are much warmer. The use of dry suits requires additional training, however, to learn how to handle the additional buoyancy of the air in the suit.

It varies. Divers use different breathing gases depending upon their needs.

For standard air, it is 21% oxygen and 79% nitrogen.

For nitrox, it can be any higher mix of oxygen, but typically either 32% or 36% oxygen, and the balance nitrogen.

For trimix, you can have almost any combination of oxygen, nitrogen and helium to suit your depth, and manage your risk to oxygen toxicity and nitrogen narcosis.

Boyle's Law: (P1 X V1)/T1 = (P2 X V2)/T2 applies to scuba diving since there is a significant change in the pressure. As the pressure of the surounding water increases with depth, you are required to use far more air from the SCUBA tank to provide for your breathing. If you use one cubic foot of air at sea-level, doubling the atmosphereic pressure as you go down causes you to use your compressed air at twice the rate. By the time you get very deep you are using your air at a very high rate.

Approximately 79% nitrogen and 21% oxygen

I thing more accurately it is more like 20.5% oxygen, and the rest is nitrogen and other gasses. Carbon dioxide only makes up around 0.03% of the air

Wetsuits were invented sometime in the1950s.

A full range of injuries are possible with diving the same as any sport. including death. a number of divers have been killed by hitting their head on the board after take off. crippling injuries that result in a person being in a wheelchair for the rest of their life is fairly common in untrained people using public diving boards.

the common injuries are sprains pulled muscles and bruises. note that injuries can occur from low heights if the entry is not correct. Also it is common for people to break their neck or back when they dive into water that is too shallow. this often happens on holidays with people diving into the sea rivers lakes etc. as well as swimming pools.