Back the truck up.
The “Bahamas” is not one thing.
The answer to the OP absolutely depends on
at least two unspecified factors.
1) where in one of the great many Bahamian islands will you be?
2) what repetitive dive schedule (number of dives per day)?
The technical answer to the wetsuit question can only be given by the numbers in the average water temperature. NOBODY but you can ever know what that means you you is YOU. This comes after numerous logged dive conditions. What works for me, or a travel agent on a FAM trip, or even a DM, that’s totally irrelevant.
L4E says it’s in the low 70’s. Not in Nassau. Where you going?
Here’s Nassau (in example) data:
Nassau Water Temperature | Bahamas | Sea Temperatures
other locations can and do vary
Until you understand what you yourself require based on water temps, there is no answer. Then factor in the number of dives per day, as your body will not recover as quickly from 3x a day versus 1x a day.
If you do not know your tolerances, bring everything you have! If you are diving in one of the well travelled places, like Grand Bahama or Nassau? You can rent (except extreme sizes), and yes, I’ll agree with the above poster, those reefs are pretty-well moonscapes.
The Bahamian “out islands” further afield still have a lot (a whole lot) to offer for divers, but not much in the way of rental wetsuits. A few liveaboards will take you to good diving, some not so much. There is a correlation.