You can buy one-time use underwater cameras for between $5 and $10. Depending on how many exposures they have, though, it might be cheaper in the long run to spend $100 or so on a waterproof digital camera. That way, you won’t have to worry about whether your pictures are “good” or not – you can always delete those that don’t turn out well. Make sure you check the depth to which the camera is water resistant, though – I’m not sure how shallow your shallow reefs are. There are a lot of digital cameras that are not specifically for underwater photography that are waterproof to a degree, but if you want something specifically for underwater photography it seems like you’d have to be willing to spend at least a couple hundred.

Zip lock bag.

Seriously. Zip lock back, cable ties the top, and fill it with caulk.

Condoms

I have one of these . They take better vid than picture but theyre pretty cheap, small, and extremely portable.

When we went to San Diego and went scuba diving, we just stopped at a CVS on the way there and picked up a disposable camera used to take underwater pictures. I think it was about $10 and the pictures turned out great. No need to spend a lot of money on a fancy one unless you are going to be using it a lot. If you take these trips often, then invest in a better quality one.

This is my favourite. (Panasonic Lumix DMC-FT1)

I bought one last year on sale just before going to Samoa and paid about $AU300. Really cheap, and fantastic image stabilization. Takes great photos. I’ve had two other Lumix cameras (again for superior low-light ability due to their unrivalled image stability technology) and I was certain their underwater camera would be excellent. I was right. :)

It’s now available to a depth of 10 metres, instead of 3 metres. You can find more information on the Lumix underwater solutions, here.