counter for small boats
Used for counting small watercraft such as rowboats, canoes, and small fishing boats. Not typically used for large ships.
湖に小舟が三艘浮かんでいる。
Three small boats are floating on the lake.
漁師は一艘の船で沖に出た。
The fisherman went offshore in one boat.
隻 is the more formal, often official/news-register counter for ships and submarines, while 艘 is the everyday counter used for boats and small craft in casual speech.
Standard kanji counter for small boats.
Kana spelling is common in everyday writing, especially when the kanji is not essential.
The kanji 艘 is composed of 舟 (boat) and 叟 (old man), but the historical derivation is uncertain. It is conventionally used as a counter for small boats.