Yes we have. Both wife and I did last April on the Sun at St Thomas.
It was our "big" excursion for the trip. I liked it, but would rather SCUBA than BOB. The wife got sea sick on the way out to the dive site and was pretty claustrophobic inside the "helmut", but all in all, its a once in a lifetime must do kind of thing.
The captain and crew are great. They have about 24 people on the boat and you BOB in groups of eight. One diver per two BOBs. You travel about 200 yards out and 200 yards back in about 20-30 minutes. Between groups you can swim, snorkel or sun bathe on the deck.
The fish and underwater scenery are incredible in St Thomas. Our diver took my underwater camera and got some great shots of a 30" barracuda and us together with fish swimming around us. I used the MPEG function on the camera and got some great video clips while we traveled along.
There was a bait ball about 500 yards long and about 30 yards deep. I thought it was coral since the water was so dark from above. I snorkeled through it and had a blast.
I have to admit, there is a claustrophobic feeling when you first get into the helmut, you have to dive down and climb in while underwater, and it does get a little confining and hot. That's why I would prefer SCUBA to BOB and will do a Discover SCUBA next time rather than BOB.
But it is a once in a lifetime thing. I would recommend it, but with the claustrophobic caveats.
Emerald Princess - September 16, 2016 - Southampton Roundtrip to the Canaries
Emerald Princess - September 28, 2016 - Southampton to Sydney
Emerald Princess - November 15, 2016 - Roundtrip Sydney to New Zealand
Star Princess - April 11, 2017 - B2B - Coastal and HI From Vancouver
Past Cruises (All Princess):
Crown - Tahiti 10/17/2015; Golden - Alaska 6/1/15; Golden - Alaska 5/22/15; Ruby - Western Carib 12/13/14; Ruby - Eastern Carib 12/06/14; Ruby - Eastern Carib 11/29/14; Grand -Mexican Riviera 03/05/14; Grand -California Coastal 03/15/14; Grand -Hawaii 03/22/14; Ruby -Transatlantic 11-29-2013; Ruby -Grand Med 11-17-13; Ruby -Eastern Med 11-05-13; Ruby -Eastern Med 10-24-13; Caribbean -British Isles 05-12-13; Caribbean -TransAtlantic 04-27-13; -Asia/Alaska 04-15-12; Grand -Western Med 10-21-11; Golden -Hawaii 04-27-11; Emerald -Caribbean Combo 11-28-10; Star -Antarctica 02-02-10; Golden -Hawaii 9-27-09; Golden -Pacific Coastal 9-19-09; Grand -Caribbean Collection 3-27-09; Dawn -Mexican Riviera 4-27-08; Island -Panama Canal 2-06-08; Golden -Mexican Riviera 9-29-07; Golden -Pacific Coastal 9-23-07; Caribbean -E. Caribbean 04-29-07; Star -W. Caribbean 04-21-07; Dawn -Mexican Riviera 12-1-06; Island -Alaska 5-22-06; Island -Alaska 5-15-06; Dawn -Mexico 10-2005; Sun -Eastern Caribbean 4-2005; Star -Western Caribbean 12-2004; Island -Panama Canal 1-2004; Sea -Mexico 1-2002; Ocean -Alaska 6-2001