The captain answers a few of your questions. "The crew knows their duties. We have not have new recruits in ages. So, I have time to explain whatever you might ask.
"I am the incomparable Captain Celeste Bloodbane!" Her name is not one any of you remember hearing before. She waits for a few seconds to see if she got a reaction, and when she doesn't, she continues, "There was a time when hearing that name sent people into a panic, even before I died! Unfortunately, that time has apparently long since passed.
"Since we are stuck on this lake, we do what we can to keep busy. It is a large lake, but not nearly large enough for our true needs. There used to be more needing passage, but with the wars going on down deeper, no one has need for our services, anymore. I wonder if they even remember we exist." She looks a bit wistful with that last part, though you can't tell for sure.
"The other side is another landing with a pier we will let you off onto. Nothing special. No town or settlement or anything. Just a pier for our use and that's it. No one bothers with this lake except to try and cross it. There are only two entrances to the lake, and both are rocky and narrow, as you saw on the side you came from. When you get off, you'll have to travel a while to find anything organized. I have no idea of anything specific, just what we have heard said in the past. There is no way for us to check it out.
"Water is a hazard of being on a ship. You learn to deal with it.
"As for why we are even here and wander, that's a longer story. We are supposed to be on the open seas, but with the Cataclysm, we ended up trapped down here. Fortunately, the lake is big, but it isn't the vast expanses of the seas, and so it still feels confining. Oh for the day we can be free of this limited space!"
You can now get a better look at the crew, and you can kinda see why the two that came to get you were the ones chosen. As you look around the crew, you see a wide array of animated corpses. A few are just skeletons at this point, with nothing else left of what used to be their bodies. Others are in various states of decay, and couple with something missing, but most intact enough to keep operating. There are even two ghosts who wander about. All of them are dressed as you would expect from a pirate in old stories, including tricorns, flouncy shirts, eye patches, and the whole lot. You even realize that a parrot you thought was just stuffed is actually a zombie parrot, once it finally moves and makes an incomprehensible sound.
Hearing the squawk from the parrot, the captain picks it up and puts it on her shoulder. "She can't fly anymore, but she's still part of the crew!"
Oliver's use of his circlet only points to below-deck. It overrides any other possibilities.