The more I dive the more I can imagine what could go wrong.

[MikeFerrara]

Hand held lights are controlable and enough IMO. I carry three because the 2 backup lights are always on my harness but I think 2 is enough for a recreational night dive.

I absolutely hate when divers wear strobes and woun't dive anywhere near them. I can't think of a nuch more irritating thing on the face of the planet...I mean I really hate em. Non-flashing tank lights are almost as irritating. Glow sticks and things like that are less irritating but still irritating and, IMO, not needed. You need to be able to see one light per diver. Good buddy skills and light handling will work just fine. Caves are pretty dark and I have yet to see a diver wandering around with any of that junk hanging off them and flashing/glowing in peoples faces.


Strobes or other lights to mark entry/exit points make sense some times of course.

 

[lairdb]

Most respondents have focused on the "running light" half of the question, and skipped the "emergency signaling" half. I'll agree entirely with a main and backup light (i.e. tool for illuminating things) and a small constant running light (lightstick or electronic substitute, e.g. EcoFlare in constant mode, GloToob, UK Dive Beacon, etc.) I'll also agree about the annoying-ness of ZOT ZOT ZOT as a running light.

However, I'll put in a vote for ZOT ZOT ZOT as an emergency beacon; the main light is good, but fairly directional; if you can see the search plane, that's great, but if you are bobbing around without a clue where to point your main light, I believe an omnidirectional strobe would be a Good Thing to have.

 

[chinadan]

I carry a Light cannon, a FaMi power LED-4 as a backup and my home-built green laser pointer.

I tried the laser pointer on a night dive (in shallow water, towards the end of the dive) to evaluate it's usefulness as an emergency backup light.

Well, apart from having a visible beam (sort of like a laser sword...come to think about it with the sound of breathing I did feel like Darth Vader... that allows your buddy to see you, the green dot is bright enough to illuminate immediate surroundings/instruments in case of an emergency.

And if you surface and either shine it at the boat (or up in the sky if the surf's up) it makes an excellent beacon. The boatman (speedboat in the Philippines) asked me to switch off the dive light so he could see better in the dark, so we used the light of the laser to illuminate the boat for off-kitting.

 

[subaquaman]

Would also put in a vote for a primary (usually come with SOS functions nowadays too), two backups and while they are not for diving with, put a ZOT ZOT ZOT strobe in your pocket. If you're on the surface and things are not going quite according to plan, they can be easily seen by aircraft and search boats in all directions.