Garmin maps since 2010 have the Cayman Islands map set included in their North American map. May help a bit for general area location and points of interest, but I do not really find it that useful. It is a small island and there are not that many roads.

Google "Testudo New Garmin Cayman" for a link to a POI file I created for some Grand Cayman tourist sites.

Snorkel air just tastes better than canned air...