Some additional thoughts or personal observations:
My SAC goes down at night, dont know why, but i am more calm at night than in the day.
If you want to attract attention to something cool, a quick flash back and forth to attract attention, then steady the beam and circle (OK) the thing in question - constant fast flashing will mean an emergency.
I agree with spare lights, turning it into your chest rather than off (it may not spark to come back on) if you want no light, i find it ok to do that on full moons or with phosphoresence (sp?) in the water, but otherwise you might still miss a bunch.
Critters that seem to come out more at night include a variety of fish, crusteceans (better for bug hunting), and invertibrates like octopi.
When going from the shore, be sure to reference the lights on the buildings as they start up - its awful easy to confuse where you are due to current drift however good your compass work is. Some say put down two lights on the shore so you can judge where you are - great when people dont steal them, so use good references.
Now to thread admin in this forum and others. I would love to sticky up a bunch of threads that are informative, but unfortunately if i did that with all those that were helpful you would never see new posts as there would be more stickies than the page could hold. The reference section on the Scubamatrix portal thing has some more info written by knowledgable sources and hopefully one on each of those topics will come up some day. A good reference book (i bought Dennis Graver's "Scuba Diving" and possibly AOW text as well as anything entitled advanced diving practices etc - i bought Jespersons) give most of these basic tips, but you can learn a few extras or what seems to work from your fellow divers as well.
