Are you sure they're all VHF.?
Could be he's a ham...
If he's from Florida most American boats seem to sport about half a dozen as a norm.
They generally have them hooked up in phased pairs which gives good front and back gain.
The GPS types could also be navtex and the american version of that called SITOR.
If he's come across the pond it'll be a fair bet that he's also got HF/MF on there and probably an external satphone antenna.
Or probably a cunning plan to disassemble important bits of the boat and chuck 'em into to the two spare liferafts before she goes down.
He's probably a scrap dealer...