, a fellow staff diver for the GOT, to help me show what all that gear's for, so let's jump right in...
SCUBA diving (which, by the way, stands for Self Contained Underwater Breathing Apparatus) is a lot like being an astronaut in outerspace. Both divers and astronauts venture into alien enviornments that aren't meant to support human life. Like astronauts, divers have to bring the air they breathe along with them. And, like astronauts, SCUBA divers float along weightlessly through their "underspace." However, accomplishing this task underwater requires a little help. Even the act of seeing clearly, or moving through the water, is made difficult by the physics of water. SCUBA gear to the rescue!
Let's take a look at Sarah as she so nicely models the gear a typical SCUBA diver wears...
That's a lot of stuff just to go swimming! But it's all necessary, and to be honest, once you're in the water you forget you're even wearing it. (Remember the whole weightless thing?) So let's break it down and shed all the mystery. Besides, Sarah's getting hot and tired wearing all that equipment!
Since a picture's worth a thousand words, let's start with some images ...
Front View (click to enlarge)
Right View (click to enlarge)
Back (click to enlarge)
Left View (click to enlarge)
Let's see what we've got, going from head to toe:
You have to wear a mask to see underwater because your eyes can't focus directly in water, they need an air space to look through. Plus a SCUBA mask covers your nose to prevent that pesky water up the nose thing.
Snorkel: A snorkel allows you to breathe while swimming around on the surface, so you don't have to use up the air you're carrying around in that tank on your back (more on that tank in a bit). Note - we don't use snorkels when we dive in the GOT.
Buoyancy Compensator (or 'BC'): This is the harness that connects the diver to that precious tank of air. But it plays another, equaly important role. It contains a bladder, sort of like a balloon, that the diver can add or remove air from. The more air in the bladder, the more the diver floats up; remove air and the diver sinks. Just the right amount of air and the diver can hover motionless. Pretty cool!
BC Inflator Hose: This is the thing that allows the diver to add / remove air from the BC. There's a pair of buttons on this hose, one to inflate the BC and one to deflate it. There's also a mouthpiece that allows the diver to manually inflate the BC by exhaling into it in the event of a malfunction.
Weightbelt: What? You mean you actually have to strap lead weights to your body to become weightless? Ironic, isn't it. Well, alot of this gear actually wants to float (including most of us humans) and on top of that, SCUBA divers often have to wear some form of thermal protection to keep them from getting cold underwater (Sarah is wearing a full wetsuit that is 7mm thick, which is just about as thick a wetsuit as they come). This thermal protection tends to be
very buoyant. So to offset all this "floatyness" a diver needs to strap on some extra weight. Of course, there needs to be some way of ditching this weight during an emergency. The weightbelt has a "quick release" buckle, allowing the diver to ditch the weight with one hand. Kind of like a hot air balloonist dropping sandbags to float back up. This analogy works espically well with Sarah, because I often say she's full of hot air.
Tank: That cylindrical thing strapped to a diver's back is what holds the air the diver needs to breathe. In order to hold as much as possible in as small a tank as possible, the air is really crammed into the tank under high pressure when it's filled. As a matter of fact, that tank on Sarah's back holds enough air to fill an entire telephone booth, or about 80 cubic feet. (Humm --when was the last time you saw one of those?)
Regulator: This is the thing that provides the diver with the air from the tank on her back, and while doing so it has to convert the high pressure air from the tank into something more lung-friendly. It's made up of several components - the most important being "first stage", which attaches directly to the tank and knocks the high pressure in the tank down to an intermediate pressure; and the "second stage", which delivers a smooth breath of air everytime the diver inhales (and provides an exit path for the spent air when the divers exhales). There is also a gauge that tells the diver how much air is left in the tank - a pretty good thing to know! - and a backup second stage, often referred to as the "octopus". Finally there's a hose that connects to the inflator hose of the BC, to the tank, and by now you know what that's for...
Fins: When you aren't able to stand, it's kind of hard to walk, isn't it! How do most fish deal with this problem? Yep - they have fins. So it makes sense to give fins to humans when they want to explore a fish's home. Check out how easy it is to move in "underspace" when you're wearing fins...
Knife: No, it's not to fend off giant squid or maurading spies. Rather a dive knife is an important piece of safety gear, to be used if the diver ever finds herself entangled in anything from discarded fishing gear to long strands of kelp. Anything that can trap a diver underwater is a potential danger, and a proper dive knife could save the day. Note - we don't use knives in the GOT either!
So that about sums it up. Actually, the sky's the limit as to the diversity and complexity of the gear that's used for SCUBA diving, but I've covered the bases here.
Next time you visit the Aquarium look for one of the divers in the GOT and see if you can pick out each piece of gear. Or better yet, visit your local dive shop and take the plunge yourself!
Happy diving.
