Reply #1: It's a solution to a question no one asked

[NickB79]

Lasers on ships are pointless compared to projectile weapons. CIWS guns that fire hundreds of rounds per second are just as effective as a laser on small targets, and a hell of a lot cheaper to boot. You can't replace large guns like those on old battleships with lasers because a lot of fire is over-the-horizon fire, which you can't accomplish with a laser (no arc of trajectory, just a straight line).

It really has no use except to look cool and futuristic.