Experienced swimmers know it is relatively easy to escape the narrow channel of the fast moving water by floating and allowing it to drag you further into the ocean or by swimming alongside the shore.
2
当他游泳时很咸的水使他漂浮起来。
The very salty water buoyed him up as he swam.
3
如果你到河里游泳,会像在海里一样浮起来,能漂出去一千英里。
If you swim there, you float as if you were in the ocean, a thousand miles away.