Bug: getting crew from icebergs breaks the boat's position (which already had a crewmember on it), making it offscreen. I think it's related to the forward movement in the animation when the iceberg breaks and the flying crewmember hovers for a while while they say "im forever indebted to you".
IDK if it also happens if you fail at getting the crewmember, or if the boat is empty (with the new crew thus sitting at the boat).
Note that while the boat's position is wrong, it's purely visual, and hovering the mouse over the correct place where it should be triggers the crewmember's tooltip.