BVI water toys carry them for $4 each with free delivery on orders over 75
Last Stop Sports charges $2.50 and is significantly cheaper than BVI water toys on all items and they offer free delivery to the Moorings and other charters - see their website for details.
I discovered that Last Stop Sports moved from the Moorings dock to Port Purcell.
"Travel is fatal to prejudice, bigotry and narrow-mindedness" - Mark Twain