入水面 meaning in Chinese

u tream face
upstream face

Sunk though he be beneath the watery floor . .
虽然他已沉入水面下19
The rocky point projects far into the water
那石岬伸入水面很远。
When meet laminar flow , the floater sometimes can see , sometimes can t see , when meet heavy flow , make the floater under the surface of water , namely the elasticity is moderate
平流时自见不见，大流时刹绠至漂入水面下，即松紧适中。