Beautiful image! I don't know which "error" you're talking about, though I'm having a bit of trouble parsing what the captain's left hand is doing.
I can always think of things I'd improve or change about the pages of the manga, but I sort of see it as a work in progress, so I just keep going. The illustration style itself tends to be less fussy than the photorealistic style you were working in, I think. (Lighting, in particular, is a lot easier.)