Watermelon's draft was 7'2". We even went to Andros Island in the Bahamas (we were told we could not go there if we drew more than 5'!) Only place I backed out of was an unnamed, uncharted cove in the Solomon Islands. We even anchored it an iffy cove in Island Harbor, OZ (? no chart handy, not sure if that's real name - we took shelter when bad weather was forecast, hung out for a week - cool!)
We negotiated a pass in Los Roques, VZ - two boats before us, with drafts of about 6' hit coral, told us not to try it if we drew that much - we, and our friends with a draft of 8' found the REAL pass, with depths no less than 10'. We spent 4 years cruising the Caribbean and Venezuela, sometimes in company with our 8' draft friends, and I don't remember any place we were excluded from except Buccoo Bay/Reef in Tobago (and so few people go to Tobago that I sometimes wonder why I mention it except that Tobago is, in my opinion, the true jewel of the Caribbean).
There are places in the Bahamas and Florida keys where our 7' draft was a problem, admittedly, but most harbors and bays had sufficient depth, just passages were occasionally difficult. Considering how many places we visited, though, it rarely kept us from going anyplace.
Fin keels are a lot more forgiving when going aground than full keel boats, which might be why we were so brave.