Does anyone know where we can rent scub gear on St Johns. We want to go on our own not with a tour company.

We have rented the Rapture Villa in St John this July. Has anyone stayed there...what did you think? How well stocked is the kitchen...or do we need to bring our own salt, pepper, spices, oil, sugar...etc. We plan on buying groceries....how expensive is it? Do you also recommend we get travel insura...