After speaking with Thornvald, with him telling me the boat is probably captured and captain fed to the sharks, I ran to the boat thinking, hey I need to try and save them. Lo and behold, a few dead bandits on the group and the captain standing there. I'll just click on him and find out what's going on. Here's the part that I don't like: The dialogue tree didn't give me any options to not leave at that point in time, Capt Teach just whisked me away back to Ashbury..hey! what if I wanted to stay on the Isle and do the other quests? I ended up going to a previous save but it really sucks that you can't confirm you want to leave or not.
i guess he was scared so he did not want u to stay(i think u can teleport back there later but i have not tried)
Nope, short of hacking (and I think someone posted how to do it on one of these Arcanum boards), there's no way to get back to the Isle of Despair.