I would second Conch Charters. Very honest people who run a company specializing in older boats. If the boat has a generator and AC you should be able to place it with them or perhaps BVI yacht charters. Without the generator it will be a tougher sell but they may still take it depending on condition and prior charter use.
If you don't have a generator onboard I would consider adding it. It's a personal opinion but I feel there is a market for a small monohull with AC that is underserved.