Grenadines and Tobago Cays diving

[Indigo1]

We are planning a trip to Grenada and the Grenadines for a month and trying to decide about taking a dive compressor and tanks or just hire. Don't mind supporting the community but so often can't get on dives or they are so pricy that one can't do too many. Can anybody help us with comments on dive charter service levels, cost of charters or restrictions on self divinging. Has anybody found a local dive guide that can escort self divers in the Tobago Cays?
Thanks Barry