Pretty straight forward, as title. You can't explore, you can't attack other players but you can attack a stronghold. I like the fact that I can do something in these 3 hours but it isn't right.
I don't know what map you're looking at but I can't see any other way of getting there from your own island.
The sea is very nice and cosy this time a year. It's great for swimming, oh and the barrels from juggs make excellent surfboards!
Not to mention all my kraken and bigger fish I have trained since I've spent so much time whipping their tails. They just pull me where I want to go.