ở dưới mặt nước dưới mặt nước 
underwater 
He brags that he can walk on the surface of water. ☊ 
Anh ấy nổ là anh ấy có thể đi trên mặt nước. ☊ Informal Expressions like: mặt nước → →
a beached whale (= one that has become stuck on land and cannot get back into the water) ☊ beach ☊
He dived below the surface of the water. ☊ below ☊
The canoe cut through the water. ☊ cut ☊
The ship's sail cast a shadow on the water. ☊ shadow ☊
These plants float on the surface of the water. ☊ surface ☊
The boat bobbed up and down on the water. ☊ up and down ☊
They ventured nervously into the water. ☊ venture ☊
The leaves floated on the water. ☊ water ☊