I have been to P.R. twice -not on a cruise- and can honestly recommend to you that you DO NOT go to the bioluminescent bay tour UNLESS it is the one in Fajardo. Otherwise, you are in for a BIG disappointment since it is FAR away, and NOT much is left of the organisms that used to 'light up' the night waters (abuse ). The boat ride you will need to take from the site takes about 30 min. (to get away from 'city lights')and then they let you "observe" for about 15 min. and bring you back. These times do not include the time to get from the cruise ship to the other boat (small - 15-20 passangers max.). Beware, ask for recommendations. I personally think it is a waste of time and $$. You will see little specks of light in the water and then they bring you back. Since you are considering going on your own, the boat ride will cost you about $5-$10. I don't know how much a taxi would charge to take you to the site (assuming this is in Fajardo). I hope this is not tooo negative or confusing. Others out there...any opinions?