1A watercraft used on seas, rivers, etc.; a ship or boat (from large ships to small boats).
大きな貨物船が港に入ってきた。
A large cargo ship entered the port.
夏休みに友達と漁船で沖へ出た。
During summer vacation I went out to sea on a fishing boat with friends.
小さな舟で川を渡った。
We crossed the river in a small boat.
2A tub, vat, or tank used to hold liquids (historically written with the same character as boat).
酒を発酵させるための木の槽が蔵に並んでいる。
Wooden vats for fermenting sake stand in the brewery.
庭に雨水をためる大きな槽が置いてある。
There is a large tank in the yard to collect rainwater.
3A counter/suffix for boat-shaped containers (e.g., servings of sashimi served in a small wooden boat).
刺身を一舟お願いします。
I'd like one boat (serving) of sashimi, please.
パーティー用に海鮮盛りを二舟注文した。
I ordered two boat-shaped platters of seafood for the party.