you may want to contact JOLLY PIRATE
give them your information and see what they have to offer
problem being on a cruise, if the ports of call are changed last minute or they are off schedule then you would not be able to cancel and receive refund if you book independently. (ex: we were on a cruise a few years ago, a woman got ill and the ship missed port of call Grand Cayman as we had to backtrack to key west for hospital. my husband and son had booked thru the internet an activity and was unable to get a refund)
my advice is BOOK a sail and all activities thru your cruise line.
in the event of missing aruba due to something like my cruise situation ........you will not lose out on any $$.
lots of the cruise lines now allow passengers to "book ahead".
in the old days of cruising that was not an option.
contact your cruise line and make the inquiry.
i do know that JOLLY caters to cruisers as does Depalm.