It's not about growing bigger, it's about playing smarter:

-- If you see the "big guild" that keeps sinking your guild ships has right maps as their common maps, then every ship from YOUR guild should also start with a right map -- don't give them maps they need.
-- Don't sail 1-by-1. Gather 3+ sets of sailing partners and sail all at the same time. Some will sink, but some will get through (ESPECIALLY if you set sail during Baal/Cerb or right after GW).
-- Don't complain to these pirates in private or world chat; they will only sink you more, as it adds to their fun.
-- Finally, if these big players are handing off maps after sinking ships, STOP ROBBING THEIR MAPS WHEN THEY POWER DOWN.

Tynon has done a lot to help smaller players in the Caribbean already: more attempts, more free maps, and half rewards even if you sink.