What settings are used? manual or automatic.
Check out Jim Spears (aka Gilligan) website for great advice:
http://pt010.da-kine.info/settings.htm
No camera will be the same, so you need to determine what looks correct for your own camera and shooting style. My camera is a Canon S50 with SeaLife strobe. With manual, I had better control after establishing baseline settings for 3 feet and macro. I fixed my ISO to 100 (should have tried ISO 50, but Im still learning) and shutter speed to 1/60th and took a series of shots from 3 feet throughout the range of f-stops at a subject that did not have any blue water behind it (the eel photo is ISO 100, Shutter 1/60, f 7.1). I did the same with a subject and blue background and with macro (the xmas tree worm photo is ISO 100, Shutter 1/125, f 8). My photos were with strobe, but you can do the same without). Without a strobe, you may want to see if you can adjust the output of your internal flash and run the scenario again.
How do you maximize color without a strobe?
Check out Jim Spears (aka Gilligan) website for great advice:
http://pt010.da-kine.info/adjustments.htm (Photoshop users) or
http://pt010.da-kine.info/adjustments2.htm (Paint Shop Pro users).
With internal flash only, you have to get close. Again, adjusting the flash output is one method.
How do you minimize blur during an action shot?
A faster ISO will do this, but you will get a grainier photo. A lower f-stop and higher shutter speed will also work, but you will loose depth of field.
And how do you prevent fogging?
I keep my camera and housing exposed to external (shaded) temperatures as long as possible. Open the housing as little as possible (changing batteries and downloading photos). I also use Sealife Moisture Muncher Capsules. You can get them at local dive shops or on the web (
www.leisurepro.com key word moisture muncher).
Most of your questions have been addressed in other forums on this website. Use the sites search engine, youll learn a lotI did.
Jim Spears shares a wealth of information on his sites:
http://pt010.da-kine.info/ and
http://kayakdiver.com/ .
Good luck.