i am mostly a solo player, (i got 2 friends who play from time to time) but i managed to make a base ontop of a rock inbetween 2 higher rocks, i've made sure nobody can build near it with a massive amount of stone fence supports, it's very defendable and after placing a warehouse there and market i managed to make enough gold to build a armoured dock and a schooner. but not before i used the respec to craft a lot of crewed cannons and puckles and placed them on strategic locations. now it's nearly impossible to raid the base, and even if they do it will take hours, maybe even a full day to get through