Sailing to Cuba is not on the same level as Rosa Parks. The embargo itself will not be influenced by a bunch of rich boaters heading off for a lovely vacation.
Actually, I think the mail idea is both clever, and could well work to bring the debate back into play.
And no, this isn't a Rosa Parks issue, not unless you consider the 423 Cubans jailed as dissidents - in the month of May alone.
The embargo hasn't worked. It's only served to provide phony justification for Castro's claim that Cubans are poor because of the US.