I wondered how it would play if you had to "re-purchase" captains... It seems a little too easy to get them back to re-deploy once their voyage is done, but we've always played it that way (by the rules).

So after about a 6 month hiatus, I brought VdG to the table again. Wanting to refresh myself with the set-up and rules, I briefly skimmed the rulebook and made a startling discovery. On page 12 of the English rulebook concerning Phase 3: Navigation, the rules state,
"Any Captain that was possibly on board returns to the appropriate Player's supply to be used for following Rounds."
The "Player's Supply" is defined during the initial setup as the items in front of the player available for use each round (i.e. action discs, reals, etc.). I certainly missed this little detail when player previously, as we have always returned captains to the recruiting supply, having to purchase them again in subsequent rounds. I can only imagine this will make a huge difference in playing and scoring as in my experience the availability of captains is what normally limits players from sending multiple ships each round.
Hopefully I am one of the few who made this mistaken oversight.