Actually, it’s old. Heck, I’ve probably posted some video of this before, just not this one.
After the big tsunami in Japan, an old fishing vessel slated for scrapping broke free of her moorings and spent the next year drifting across the Pacific. Eventually, in April 2012 the USCGC Anacapa was dispatched to sink the derelict hulk. A 110’ Island class cutter, her main battery is a Mk38Mod1 M242 25mm chain gun.
The gun has an effective range of about 3000 meters when mounted on a Bradley. But a Bradley is a fairly stable firing platform when stationary. A bobbing cutter shooting a manually pointed gun has, as you can see, a somewhat shorter effective range. That’s one reason why the Island class replacement, the 154’ Fast Response Cutter, has the gyro-stabilized, remotely operated Mk38Mod2 mount for the gun.