I took the night dive course, great fun!! One of the most usefull things I learned was how to set up my lights on the shore { triangle shape with two additional lights down the center} to ensure that I was able to find my way back to the appropriate exit point close to my car. If it is very dark outside, no moon, rain ect. it can be hard to know how close you are to the car when you surface, lol. I also learned some cool tips regarding dropping a strobe at the exit point under the water to allow me to exit at the correct spot. All this as well as proper dive light technique { learned how not to blind anyone, lol}.
Tom