Maturin was still, honestly, both awed at the creatures he'd already seen-- Sparrow's scolding to stay away from the edge had done little to sway the doctor-- and sure that this was some elaborate fantasy on the part of the pirate captain. However, he would take his role in the matter seriously enough. Perhaps in doing so, he would help the man get this out of his system.

"I'll take one, if you can spare it, Sparrow."