Jin Yoon is somewhat sheltered aboard, as much as you can be sheltered aboard a sailing vessel, and she doesn't know about their new crew member or the unfortunate circumstances surrounding his 'volunteering'.
She also rarely looks up.
Thus, when she does go outside to breathe the currents and comes across an unusually tall shadow, she makes an assumption.
"A bright and fortunate day, Captain," she murmurs, bowing so that her long braid falls over one shoulder.