For the past few yaers I've been using this combination, not very seriously as you need to be a good diver before you can get any decent underwater pictures. However, now my underwater control is better I've just about reached the end of my tether with this combination. Raw is unusable on the 8080 under or over water, which loses me the the flexibiity of changing the WB later. Secondly, the menu system on this camera is slow and a bit glitchy anyway which makes fast changes underwater diifficult. The built in flash is useless, however, I'm not prepared to get an external strobe for the camera as the u/w auto focussing is also hopeless. Manual zone focussing is very diffficult and I haven't succeeded with this.
I'm not sure I'm ready to commit to the expense of a housing, port and external strobe for my 5D. The G9 takes an underwater housing but with external strobe that looks quite expensive, although it does have usable raw. Another one is the Ixus 90 (Elph790 in US?) . Seems to me priority is; 1. AF that works u/w; 2. decent macro mode;3. either Raw or decent underwater WB setting, 4. connection for external strobe