My opinion........ while the beak and 3 ft short jokes are funny, more than likely 98% of the drivers on the road will not understand it. And then over 50% of boaters will not get it. Not all boaters know what Fountains, AT's, OL's and BT's are. They just know of all these being a 'Cigarette' style boat, and this is probably only because of Miami Vice.
I think the more generic ideas like 'IGOFAST' or 'XXBOATXX' will be more understandable. Nothing worse than reading a vanity plate and not having any idea what it is saying. Why spend the extra $40 if only a few can get the drift?
Kinda like my plates. Simple, yet understandable.
'98, sheesh, I really ought to drive this thing!