opiniongirl:underwater lazer pointer.
Neat, but absolutely useless.
You probably had one of those low wavelength reds in the cheap plastic housings. The high wavelength reds are considerably brighter, and a real hoot on night dives. I have a high quality french model.
But once green wavelength models for underwater use become available, I'm all over that. Green has much higher penetration, and human eyes are best adapted for seeing it. I want I want I want.