Underwater TTV

I'd really like to try some underwater photography, but the cost of the equipment is a bit prohibitive at the moment.  However, Photojojo had instructions for making an underwater TTV with an old TLR camera (which is essentially just a box with some lenses and so doesn't have much that can be upset by water) and a Pringles tube (or similar). So I rushed out to buy some crisps and duct tape, filled the bath, then realised I didn't actually have anything very interesting to photograph.  So here is

 a polka-dot duck

the TLR being waterlogged (I quite like this one)

an amethyst (not very clear).  This one was actually completely underwater, which seems to have upset the focus.  I think my technique needs some work...