Next month I'll be taking mine underwater for the first time.

A: What mount works best for you? Ideally I would not be visible in the shot.

B: What resolution setting do you like?

If you're going underwater, be sure to upgrade the housing with the underwater port. Much sharper images.

The underwater port really makes things sharper, and it's relatively cheap. I'd think that using the headband may give you the best viewing position. A chest harness would also work, but you'd likely find it awkward with your scuba harness, BCD, regulator hoses, hands etc.
Mounting on your head would keep all of that stuff out of frame, and since you're not likely going to be snapping your head around suddenly ( the problem with headmount shots on motorcycles, etc.), your footage won't be prone to making the view nauseated

Next month I'll be taking mine underwater for the first time.

A: What mount works best for you? Ideally I would not be visible in the shot.

Head mount is great, but you need to consider the bubbles from the respirator affecting the shots.

B: What resolution setting do you like?

The best low light setting and Res for underwater is R5 1080p at 25/30fps.
Auto white balance can be an issue when the available natural light drops to a certain level, highlights will suddenly go red, so be aware of that.

A flat lens port is a must have or the footage will be very blurry, filters will rob light, do your white balance in post. If you're the handy type, consider making your own flat lens port. The one made and use is the only one that will work in R3 or R4 mode and not vignette.
I made one further mod not shown in the pictures, the area inside the black "O" ring is now painted flat black to eliminate light reflections.

>No Vignetting in ANY mode including 720p.
>Removable front plate to access bubble lens and change if desired.
>Very lightweight.
>Filter gel can be placed internal between the black seal which also retains it.
>Room for a circular washer shaped antifog pad internally if required.
>Replaceable front flat port if scratched.
>Proven design concept i.e. other deep water camera housings are made like this.
>Gopro housing remains fully sealed.
>Front flat lens can be removed rendering GoPro as original for land based shots.

http://img704.imageshack.us/img704/3792/top8335818.jpg
http://img191.imageshack.us/img191/9623/perspective8326948.jpg
http://img202.imageshack.us/img202/1253/perspective28322126.jpg

GoPro underwater Lens Fix Test R3 Mode on Vimeo

I can't seem to find the answer to this simple question anywhere, and that is, does the GoPro2 shoot sharp footage under water? Or does it too meed the 'flat front glass' modification?

Tom, you really should visit the Gopro user forum and have access to the experience and sharing of ideas of over 10,000 members, link is in my sig.

Yes GoPro HD2 needs a flat lens fix of which there are many available. GoPro themselves have a fix and new housing available soon for HD1 and HD2.

http://img194.imageshack.us/img194/4381/goproflatfix.jpg


However, with the standard dome housing, if you rotate the Gopro camera lens about a quarter turn outwards in it's threaded tube, the focus will be spot on under water with the existing dome case lens. Of course it then will no longer be in focus above water. But perfect solution for divers wanting a dedicated underwater fix. Yes i have done it, full details on the forum.

One SCUBA tip came from some feedback on an item I am familiar with...

" I took the headband lifejacket scuba diving today and the headband fell off and the camera sank. My dive buddy grabbed it off the floor of the wreck so, fortunately, nothing was lost. At pressure, the air in the cell pockets is squeezed to less than half its original volume making its buoyancy less than half of what it is at the surface. We were at about 45 feet when it fell off. The bright orange band did show up well. I was using the scuba housing which is a modified regular housing so the weight is about the same. Just thought you should know and maybe warn divers that at-depth, the headband and lifejacket floats will not work.

A lanyard is the better choice for divers because all air-filled floats will either crush or loose effectiveness at depth."

Jim