There are a couple of 4-5 days that go to Labadee/Jamaica, Coz/Belize, Grand C/Coz. Coz has a variety of things to do (we usually cab to a beach club or go to Chakanaab (?)). Most Carib. ports are superior to the Bahamas, IMHO, plus the weather/water is much warmer. I am not a big fan of Jamaica, unless doing a guided excursion. Both Coz and Belize have excellent snorkeling. Since you are taking teens, I would recommend a bigger ship with flow rider, etc. Independence does 4-5 days out of Ft L March 2016 and goes to Belize. Coz/Belize on the Indy is a great option for teens, both for the awesome ship (flow rider, ice rink, etc.) and ports. I would definitely pick that over Bahamas.