We are going to travel around the world on a cruise linerWe are going to travel around the world on a cruise liner
A beautiful shell on the smooth surface of the seaA beautiful shell on the smooth surface of the sea
The sea foam of the blue sea rolls onto the sandy shoreThe sea foam of the blue sea rolls onto the sandy shore
Часть океана — большое водное пространство с горько-солёной водой. Большое количество чего-н. ( высок. ).