The ever-excellent Congressional Research Service report has all the pew-pew detail that you could possibly ask for: <a href="http://fas.org/sgp/crs/weapons/R41526.pdf" rel="nofollow">http://fas.org/sgp/crs/weapons/R41526.pdf</a>
well, given that cheap drones (glorified RC planes, google North Korea drones for how cheap and glorified it can get:) are being actively developed and started being used by everybody (including Iran), the laser is one of the best (price/performance-wise, not that anybody counts money here, yet using full fledged anti-aircraft missile against a much cheaper drone - you can just run out of the missiles :) tools for the job.<p>Not sure about that specific laser, yet US has also tested a truck mounted laser able to hit various projectiles like mortars and unguided missiles (and probably artillery shells with some success) - the targets that classical navy CIWS systems may have some troubles with.
The best part? They're using commercial welding lasers:<p>> The prototype focuses the light from six solid-state commercial welding lasers on a single spot, according to a July 31 Congressional Research Service report.
I'd like to see a test fire video of this. The question I have is how long is a damaging shot? In rough seas the boat can rock and pitch. If the shot has to continue for several second, you would probably need to stabilize the assemble since a small change in position could mean moving from the target to well off the target.
The U.S. Navy has been looking for some option to use against small boats short of blowing them out of the water. US Navy ships have at times swamped suspected pirate boats with the wake from a warship, but it took a few tries before the boat gave up. A moderately powerful laser weapon is a useful option for that. The Navy can start with "dazzle" and crank up the power to "punch holes in boat" if they don't surrender.
I doubt that this will be more effective than conventional projectile-based weapons. Also, lasers that need this kind of power usually require and release chemicals that are very damaging to the environment. It'd make a lot more sense to install this on a ship with a nuclear reactor as a power source. But then again, I guess it'd be unlikely that the laser is used because those ships usually aren't at the front line.