No info on Gaviota, we didn't visit there, but based on our time in Cuba last winter, there's certainly no problem in the boat staying beyond 60 days, it's just you that needs to get out - I think Canadians get 120 days? - even if it's just for 24 hours; I recall
being told that boats were OK for up to twelve months, but met a couple of owners who'd been moored in Hemmingway for several years, so there must be ways around it? As noted earlier, there are a lot of boats laid-up afloat in Marina Hemmingway, we also saw others at both Santiago and Cienfuegos; security
isn't a problem at any of them as the Cuban authorities keep a close eye on who goes on/off/near the moored boats; but for weather
protection, I'd choose Hemmingway ahead of Cienfuegos with Santiago a long way third.