So I was researching the feasability of this when planning my upcoming RCCL trip with a 3 and 8 year old. This is what I found - the pros in here, please feel free to comment if I've made an error:
St. Thomas --- visit ST JOHN
- get taxi ride (about $10 per person each way) ($80 total for 4 of us) to the Red Hook Ferry Terminal , takes about 20 minutes to get there - CASH ONLY
- Red Hook Ferry Terminal - buy a ferry ticket $8.15 each way / $16.30 round trip per person ($65.20 total for 4 of us) ---- leaves on the hour, every hour
- takes you to Cruz Bay in St. John (ferry ride is 20 min appx)
- Once there, get an open air taxi on left side of terminal - Cruz Bay to Trunk Bay is 3 miles, about 10/15 minutes drive
- $6 taxi ride each way to Trunk Bay ($24 total x round trip =$48 total for the 4 of us)
after 2017 hurricane, many facilities are damaged so maybe free entrance, maybe not ? If not, appx $4 per adult, kids free?
so appx $201 total for all of us
OR, through the cruise line: (RCCL)
St. John Trunk Bay Beach Break From $79.00 / per adult $69.00 / per child = $296 for all four of us and it's all taken care of for us --- only FOUR hours, though
(maybe discounted for black friday deals???)