bubblegirl,

I've used Aquapacs for mobile phones (I work in water) and although they are very effective, I've found they start to leek after a few months of use. The seals are fine to begin with, but I've found they start to wear pretty soon depending on how much usage (wear) they are subject to. It doesn't matter if a mobile gets slightly damp as they're cheep enough to replace (work pays anyway!), but I certainly wouldn't trust one to put my 50D in or any other expensive camera. You'll also find the optical quality of the port will prove frustrating and they are actually quite difficult to use under water. Because they are quite buoyant and you need to keep air inside them to compensate for the pressure change (to prevent it squeezing the camera), some of the buttons can be difficult to press and the high buoyancy just makes it tricky to compose the shot. I'd either buy a proper marine housing (£££), or stick to a compact digital and marine housing. I do a lot of diving and use a SeaPro marine video housing to shoot video (example here), I prefer to see Sharks swimming than static and it comes in useful if one gets a little too close! There's some great hints and tips for underwater photography on BSAC's website. You need the right tools for the job. I've seen too many expensive cameras ruined by cheap housings, although many were user error in not correctly sealing and testing before submersion. There's a dedicated underwater cameras thread for more opinions.

Darren

Are you talking about a dedicated packs, or a general purpose waterproof bag?

Dedicated bags (eg from Uwatec) will screw fit an optical port to the front of the lens and can be Ok.

I've got one of the latter - it's hopeless. Have to attempt to manoeuvre the camera into position to point it through the plastic while keeping fiongers on the shutter button etc, then try to see the viewing screen through a layer of plastic that's reflecting light... If you dive with the bag it will compress and push the buttons for you - ooops!

If you want to try one pm me your address, you can have it!

But personnally I'd look up a cheap-ish digital camera plus housing (Fuji z100 plus housing is going for just under £170 at present from the right place). It'll give you much better pictures, and a bit of video if you want.