Lasers could also be used for communication purposes underwater. If humanity ever decides to build structures underwater, then this could be a very important part of being able to communicate effectively with the surface.
Scuba divers need to be able to see underwater and laser pointers can help them to identify objects or to communicate with other divers. For instance, using an underwater laser pointer to draw someone’s attention to something that he or she is exploring is a good idea.
It’s an important part of a scuba diver’s gear that most people wouldn’t want to be without.