- the expanse of sea away from any coastlines, bays, inlets, etc.
- high seas
open seaopen sea
A boat on the open sea.
The open sea is the middle of the ocean or sea without land in sight.
An example of open sea is the middle of the Pacific Ocean.
- This statement holds good for the Gulf of Suez, in which the water is much salter than in the open;sea; but in the Gulf of Akaba the distribution is exceedingly uniform, nowhere differing much from an average of 40.6 per mille.