I'll tell you all how we got it.
I took yesterday to play. I started playing with 3 friends, over time more friends were asking if we had a place to them to join.
It was then that, luckily we found a sloop sailing away. We said we were friends and asked if did not want to "sell" the boat for what we had on the ship. He agreed, called one of us to his crew and formed an alliance.
We went to the outpost with them, we sold everything. The guy and left. 2 boats in the fleet.
You can do this till all ships are on your fleet.
