Some cameras have a single-click, white-balance adjustment button. Setting white balance manually
varies between cameras.
When at the depth for your shot,
point the camera at a white card strapped to your wrist and press the single click button. Some
use the palm of their hand. Hardly seems perfectly white to me.
The camera adjusts it's settings so that white is true white when photographed.
Then point the camera at your subject, and shoot as normal. The result is correct
It is an extremely simple, one button push with the
Canon Powershot S90 and S95.
Why not try the the S95 (and newer models) presets for 'white balance = 'underwater'?
Why lose dive time, or take your eyes off a fish target to adjust white balance? Why
bother when many cameras do this automatically?
I have seen beautiful shots from the Canon S series using one-click. Perhaps you
get very quick at what appears to be a phaff.
I'd still recommend a camera with an effective underwater white balance feature but the single click button
is an option that clearly works.