Hi,
ok, so using a red laser rointer underwater might not be that efficient, and I guess green lasers aren't that common... but what about fitting the gun with som sort of scope like the military issue AimPoint (
http://www.aimpoint.com/o.o.i.s/67)?
Ok, I admit it, it's a bit Arnold, but what the heck... Cost aside, might it just work?
//Per