Ok here's the deal. The Bluefin HC3 can access three of the six visable controls in the p-menu. The three we think are most useful are Tele Macro, Smooth Slow Motion, and White Balance.
There is some set-up to move the buttons to the right column of a 2 column by 3 row grid and to set the WB once to highlight the one push button. But that's all a one time deal. Once you've set one push, the camera seems to remember that you want one push.
So after set up on the right side of the p-menu should be
TELE MACRO
SMOOTH
SLWREC
WHITE
BAL
Here's the sequence for getting to "one push white balance"
Push the left knob to activate the p-menu
push the left knob to activate the White Balance menu
push the left knob to activate "one push white balance"
In this mode you can record and zoom and reset the white balance multiple times with one push of the left knob. If you want to adjust the manual focus or exposure, you'll need to exit.
If you want to then shoot in auto white balance, you can push the "easy button" twice.
If you want to avoid all of that and are willing to spend a few hundred bucks more, check out the Sony A1U. http://news.sel.sony.com/en/press_room/b2b...lease/9103.html 
It's a really nice camera and has a programmable button that for uw is used for "one push white balance.
Hope that is clearer than Monterey Bay during a bloom.
:-) Barrett