there are countless rafts all over to steal one if they needed one, you can also get one easy on freeports, and are not hard to make.
same with sloops, it shouldnt take 8 hours for it. just dont leave it on the beach like a newbie, thats how it is on ark too.
if you dont wanna lose your boat hide it, defend it with different time zones members, npcs, etc.
and if you do lose it then try and steal another one, or build a new one.
i mean, stealing is the least of the problems, any group bigger than 20 can sunk your ship by just standing there, or zergs destroying it with grenades, or alphas with whatever they use. just like ark.
if you give people the change to steal anything, then it wouldnt matter as much if someone steals or wipes it