Guns run out of ammo. If this isn’t a chemical-fueled laser, the laser can fire as long as it has a sufficient power feed.
Also, it’s kind of trivial to armor a boat against .50 BMG these days, if only on the frontal surfaces.
Hypersonic Chinese and Russian missiles can’t
outrun the speed of light laser weapon, that’s
why we need it. When they go fast we go faster.
Will a polished, shiny surface (like a mirror) not defeat a laser?