I would have thought the coast guard should have sunk the vessel if it couldn't salvage it rather than leaving it floating around to present a hazard. Seems the conditions weren't so bad that they couldn't paint a legible message on the hull. Doubt the AIS would have continued working or it would have been salvaged within the four plus months.
I guess that's one of the worst things about multihulls, you just can't sink 'em!
All that foam core and no lead makes them a pain in the arse to get rid of! 
