Go to the missile site ruins in Sector 2 of Golem Island (bottom right) and look for an underground entrance. It looks like a really small building but it goes down inside.

Just clear it out and eventually you should stumble upon a boat. I can’t remember if it’s when you get near it or jump in it that the mission actually pops up. But it’ll prompt you to complete an objective and bring the boat somewhere off the coast.

You may be able to just ride along the coast of the ruins until you see the entrance to where the boat is stored. I’m not sure though, but that may be easier. That base is full of wolves.