I copied the following discussion of cell phone service in the Bahamas from the MTOA ListServe.

I called Vertizon (my cell phone service provider) and they assured me that  I will have a service in Bahamas (where the Batelco signal exists) and that the Verizon system is compatible with the Bahamas one. There is just an additional $1.80/min roaming charge — still cheaper than alternatives, like buying  a phone there, or sat phone rental. Can anybody on the List confirm that this really works? Thanks,
Raoul

If you have one of the newer cell phones (tri-band or quad-band) they should work fine in most parts of the world. The older phones will not work!
I used my off-the-shelf tri-band AT&T cell phone in St. Martin, Saudi Arabia, and the Bahamas. Our aircard worked as well in the Bahamas. Note however that a gazillion dollar per second roaming charge does apply. We now have the quad-band LG Slides.
Check the capabilities of your cell phone itself. If you have at least the tri-band it should work. Check you Verizon plan for international coverage. If you don't have it, and they require it add it for the nominal monthly charge.
If you anchor in a harbor with open access WiFi (Marsh Harbor), use Skype (it's free) except you'll want to pay the $3.00 monthly charge so people with landlines and cell phones can call you and you can call them without any per minute additional charges. Also, we got the standard phone number ($20 per year) so that people can call use direct on WiFi from a landline or cell phone.
Hope this helps.
Bob