Sarel spent a great deal of his life on boats of all sizes. He traveled from Solstheim to Skyrim on a boat. From Hammerfell to Cyrodiil. From Morrowind to Akavir and back again. He spent seven years on a boat before being shipwrecked on Akavir. He's also taken part in building two boats. 

He knows his way around a ship, I'd say.