Dee, ever since a friend of mine told me a story about how a barracuda got curious and decided to charge my friend's flashlight, I have been very paranoid about attaching any kind of light to my body,let alone my head. :11:
Of course now with my new camera gear, I think I would rather have a barracuda taking interest in my head than my camera
Anyhow, Wolverrine, what kind of tray/arm combination do you use. Some amrs such as ULCS or Sea and Sea has a little gadget for you to attach a small flashlight to the arm.
I can't remember which brand but it may be Sea and Sea who makes a rubber strape that go around a strobe that will let you mount a small flash light as well.
If you get your underwater photography gear locally, they should be able to help you with mounting a flashlight either on the housing, the strobe or the arm.