My wife and I went to Cuba twice in the sailboat -- once in February of 1996 and again in February of 1997. Stayed at Marina Hemingway, just west of Havana, the first time, and went from Marathon in the Keys to Varadero the second time. In the marina at Varadero after a few days we decided that having the boat in bow first was a mistake, so I used some ropes to push it out and turn it around. Well! You would have thought I committed a cardinal sin! They thought that I was going to leave without permission, I guess, and came running down and shouting -- guys with guns! Whoa! My Spanish is not that good, but I finally managed to convey what we were doing.
It was great cruising, but make no mistake, it was a police state. We got boarded many times, and although they were always courteous (well, most of the time anyway) we always felt that there was an iron fist in the velvet glove.
In some ways I hate to see Cuba get to be a tourist destination (U.S. I mean, since it has been one for a long time for other countries), but it will be good for their economy I suppose.
And by the way, the Cuban people are absolutely wonderful. I have nothing but praise for them.
And if you do get a chance to go cruising there, the Nigel Calder cruising guide was the best we found (although now that it may open up there will of course be others.
Cheers,