We use really small slow led flashers, they are so dim you don't see them unless you are looking for them. There are four colors and five of us, so my wife and I use one color and each of the kids has a unique color. They are twist on twist off.
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
When I do a night dive with an operator who requires it, I dive with one of these from Dive Gear Express. It is constant glow, not flashing and is not overly bright. The battery lasts a very long time.