If you haven't already noticed, Vimeo is chock full of tons of terrific videos shot in and around water. Whether it's a homemade video of kids playing in a backyard pool, free divers plunging to world record setting depths, or inspiring music videos for some of today's best music, it's all awesome and it leaves you thinking, how do you shoot that?

Well, my nautically-inclined videographers, let's set sail on the great ocean of knowledge and discuss. The first thing to consider is location. Are you going to be shooting in a kiddie pool or the chilling depths of the great Pacific? You'll want to plan according to the type of conditions you'll be facing. If you're just paddling around the pool there are a number of DIY solutions to protecting your camera. With just some PVC pipe, some silicone grease, and a bit of ingenuity, you can capture aqua action pretty easily. Check out ianusher's homemade housing:

The case that you put your camera inside of to protect it from the watery elements is called a housing. A lot of folks have figured out inexpensive ways to protect their cameras and allow them to record imagery. I would recommend this primarily if you're shooting in a controlled environment like a pool, small river, or just paddling around the surface . Once you have to take into account things like waves, significant depths (anything beyond 10-15 feet), I would recommend buying a case.

What should you look for in a case? The gasket, or the little o-ring that gets compressed by the housing lid, is an important element. A quality gasket should be free of debris (especially the nefarious enemy know as sand), have no tears or breaks, and it should fit really snugly. Remember, that little bit of rubber or plastic is all that's between your camera and all the water you're swimming in. The second major thing to look for is ergonomics. You want a housing that allows you to control the various buttons and controls on your camera with relative ease. The biggest downside of housing is cost. Unfortunately some of the best choices for underwater housings can be downright expensive. In some cases the cost of a housing will actually exceed that of the camera, but when it comes to protecting your gear it's probably worth it. If you'd like to see underwater housing put to good use, check out Sarosh's jellyfish video made with an Aquatica housing:

Here are some other important factors to consider:

Depth: You'll want to make sure your housing is strong enough to withstand whatever depth-based pressure it will be subjected to, this is of course a huge deal if you're SCUBA diving and dealing with increasing water pressure as you descend. Make sure to check the manufacturer's specifications to see what depth the housing is rated to perform at.

Buoyancy: Your camera and housing together will either be postively buoyant (it wants to float up) or negatively buoyant (your gear sinks). Ideally you want it to be neutrally buoyant, meaning it just kind of hovers and hangs out next to you at the depth you're shooting at. You can adjust the buoyancy to an extent by adding on weights to make it float less, but in some conditions floating can be good, like when shooting surfing. Surf-specific housings are positively buoyant to give the shooter's arms a rest, since they shoot mostly on the surface of the water anyway.

White Balance: Light interacts with water differently than it does with air. Part of that science means that reds are lost first as you descend into water. So here's a little trick I use when shooting video underwater: once you're at depth, aim your camera upwards and use the (hopefully) glassy surface of the water to adjust your white balance manually. It's not a perfect fix but it works pretty well, and hopefully it will keep the colors in your video from looking overly blue-green. For more about white balance check out this lesson.

Humidity: You've got your camera in its housing, you've checked the seal, the battery and memory cards are ready to go, and then oh no! Why is there water inside my housing?!? Welcome to dealing with humidity. If your camera goes from dry to humid air rapidly, you'll get condensation on the inside of the housing. To prevent this, place a silica gel pack in the housing with the camera, it'll absorb humidity, preventing water condensation. Another trick is to give your gear time to acclimate to varying humidity levels. If your gear has been in air conditioning for hours and you bring it out to humid air you'll have condensation form inside. So let your housing breath a little in the humidity level you'll be using it at.

Optical distortion: When light travels from water to air you get some degree of optical distortion. This is what's behind all those stories about a fish "this big" that got away. Some people don't mind the image magnification, others do. Depending on your housing setup you might not be able to do much, but luckily there are some cool options out there to help mitigate distortion. Check out the GoPro dive housing that Tom Guilmette recommends here, and note that some companies sell housing attachments to compensate for aquatic distortion.

Visibility: Depending on where you shoot, visibility might be something completely out of your control. Seasonal variations, storm frequency, pollution, and other elements you have no control over (like plankton blooms) will affect your visibility. One day it might be great, the next you might not be able to see your hands in front of you. So read up on current local dive conditions and plan accordingly.

Movement: Water is about a thousand times denser than air, so it actually helps smooth out some of your natural handheld jitter. But as always, be mindful. Don't go swishing your camera around unless you want to make your audience seasick. When it comes to shooting in big water, you have to find a way let the wave movements and currents compliment your shots. Try not fight it, this may be cliché, but go with the flow! Finally when you're shooting things in motion, be it people, animals, or waves, keep the camera still, or move it deliberately in one direction. Try letting the subject move in and out of frame on its own.

Story: I love seeing fish, dolphins, and all the wonders of the sea as much as the next aquanaut, but that can only take you so far. If you really want to engage your audience, try to convey some sort of story with your underwater video. Pretty images are indeed pretty, but think about what message you want and build a story from there. For inspiration check out Danny Cooke's amazing story about a retired commercial diver:

Test: Before you jump into a pool or the ocean with your gear, test it. Something as simple as dipping the DIY case you've rigged up or the housing you just bought in a bucket of water to check for leaks is a really good idea. I recommend testing first with an empty housing, no need to risk your camera on the maiden voyage.

Wherever your aquatic adventures take you, prepare your gear methodically, test it out beforehand, and watch out! You never know when a creature might come along, snag your camera, and decide to play videographer: