I am trying to decide how to upgrade my underwater equipment for snorkeling. Above water I use the Nikon D300, but do not want to invest many thousands of dollars, nor do I want to be transporting very bulky or heavy equipment. Underwater, for snorkeling I have been using the Olympus SP350 with Olympus housing but am frequently troubled by how slow the camera is. I have considered an underwater bag such as the Ewa-Marine for the DSLR (I had success many years ago with a film SLR in a Ewa-Marine bag, but am concerned about the digital SLR in the bag). Now, I am leaning toward the Canon G10, G11 or S90 with Canon housing. I would use the Canon primarily as an underwater camera and back up to the D300. Which of the Canon cameras would be best primarily as an underwater camera? Also, for underwater use, would the picture quality and ease of use be better with one of the Canon cameras in Canon housing or with the DSLR in Ewa-Marine bag? Thank you very much.