A couple of our divers just returned from a wonderful trip to the Philippines. One of the tales they were telling is how a professional underwater photographer, that was along on the trip, would use a red light for setting up the shot so that he didn’t spook the fish prior to taking the shot. This got me thinking about some of the group night dives I’ve been on and how the lights go crazy and it looks like the premier to a Hollywood film in the 1930s. So I’m going to take some time and pontificate on Dive Light Discipline.
If you are diving in the clear waters of the Caribbean, odds are that you really need very little light just to look at all the wonderful aquatic life. The human eye is capable of gathering in and processing images with very little ambient light; if you give the eyes sufficient time to adjust. In general, nocturnal animals don’t like light and if you spotlight them with a big video light many will retreat into the shadows long before you get close enough to see them.
So, you’ve just finished letting your eyes adjust to a low ambient light environment and BAM! your buddy shines his or her light right into your eyes; ruining your night vision for the next 30 minutes. So the first rule of Light Discipline is, “Never shine your light into your buddy’s eyes.” Any time you need to look at your buddy keep your light aimed down and only raise it up if you need to see them a bit better.
Which leads me to, Why would you possibly need to see them better? Well the most likely culprit is that they are trying to use hand signals and doing a lousy job of it. If they don’t light a side of their hands facing you, you can’t see the signals. “When using hand signals at night do NOT shine the light out toward your buddy.” is the second rule of dive light discipline. Shine the light so that it crosses in front of your body and illuminates your hands. If the light beam gets to shining straight at your buddy all they will see is stars like they just had their picture taken.
Finally the third rule of light discipline is, “Use your light with smooth fluid movements.” Move your light back and forth in a slow rhythmic pattern as you swim along. Try to cross your beam/spot in front of your buddy’s view every 20 to 40 seconds and ask them to do the same. This makes it very easy to keep track of your buddy. Violating the rule of smooth fluid movements will alert some divers to a potential problem. If you jerk your light around and aren’t having a problem you risk desensitizing your buddy to a potential emergency situation.
Want to learn more about night diving? Stop by one of the shops and sign up for a PADI Night Diver Speciality Class. While you are there you can check out our dive lights, tank markers, and camera strobes.
Today is a good day to dive!