Number + 艘 + Ship/Boat Noun
The classifier 艘 (sōu) is the measure word used specifically for boats, ships, and other watercraft. Like all Chinese classifiers, it is placed between a number and the noun it modifies. For example, 两艘船 means 'two ships.'
港口停着三艘大船。
Gǎngkǒu tíng zhe sān sōu dà chuán.
Three large ships are docked at the port.
远处有一艘渔船正在靠岸。
Yuǎnchù yǒu yì sōu yúchuán zhèngzài kào àn.
In the distance, a fishing boat is approaching the shore.
这艘船已经有两百年的历史了。
Zhè sōu chuán yǐjīng yǒu liǎng bǎi nián de lìshǐ le.
This ship already has two hundred years of history.