you'd have to be a very experienced sailor I think, more of a yachtsman than a sailor. a 30 footer is a big boat!! even a 16footer would be a handful, this is from persons with more experience of boats than me, i'm a landlubber!! if your going to go that route, you need to know what your doing, its not a case of going down the local marina when SHTF and nicking the first boat you see. the one my BIL uses has razor wire all the way around, and entry is via key card-exit the same way too, so its not as simple as just snipping off the padlock!!