Meliva takes out a small charm.
Nail this into the captains quarters, and that will keep it in place. Don't ever remove it. Least not while sunlight touches the ship. I mean unless you ever decide you want to explore an old hideout where Enrika kept this ship during the day. Could be very profitable. Could be suicidal. Old mage hideouts are rarely safe. I wouldn't risk it without a wise old witch or wizard with you.
But journeys for another day that may or may not happen can be done another day. For now, it's nearing time to seize the ship. Are you ready?