This is the 7366th most frequent Chinese word.
艇
"艇" means "boat" or "small vessel."
The word '艇' here refers to a specific kind of watercraft, specifically a 'submarine'.
我昨天参观了一艘潜水艇。
I visited a submarine yesterday.
In this context, '艇' describes small boats floating on a lake.
湖上漂浮着几艘小艇。
Several small boats were floating on the lake.
The term '艇' here refers to a type of boat used specifically for rescue purposes, a 'lifeboat'.