Wolverstone, captain of the ship Atropos, is the only one of his profession willing to take Geralt of Rivia from Free City of Novigrad to so distant Skellige Archipelago. Of course as he is enterprising individual he wants some coin, precisely 1000. He dies during the skelliger pirates attack. For this reason, you can find his body and retrieve your 1000 crowns from it. When the cutscene ends, go to the nearest ship and search for his corpse right behind it. You should recognize him by his colors.