Do you have to sail out of Grenada? Have you considered sailing out of St Vincent? Most of the grenadines belong to them anyway. If you are willing to leave from St Vincent, you could use Barefoot charters. When I was living down there they had a nice fleet of boats starting at 32'. You could bareboat or hire one of their captains if need be. They also had an option of starting out with a captian, sailing to bequia with his assistance, and then doing the rest by yourself. Either way, you will have a great time. The Grenadines are a wonderful place!