noun
lighter; tender; small boat for unloading cargo from a larger vessel
A small boat used to ferry goods between a large ship anchored offshore and the shore or another vessel. The term is somewhat specialized and may not be widely known outside maritime contexts.
港の沖合で、瀬取り船が大型貨物船から荷物を積み替えていた。
Off the port, a lighter was transferring cargo from the large freighter.
はしけ is a more common term for a barge or lighter used in ports, while 瀬取り船 is a less frequent, more specific term for a boat that unloads goods from a larger vessel anchored nearby.
Compound of 瀬取り (sedori, 'unloading cargo from a ship at anchor') + 船 (fune, 'boat'). The exact historical derivation of 瀬取り is uncertain, but it likely relates to the maritime practice of transferring goods in shallow waters or near a sandbar (瀬).