At dawn we had completed most of the open-sea passage on the return journey.
The open-sea or pelagic haunt includes all the brightly illumined surface waters beyond the shallow water of the shore area.
These open-sea young eels are known as Leptocephali, a name given to them before their real nature was proved.
Shipbuilding, including steamers for open-sea navigation, is on the increase.
the middle of the sea as opposed to that abutting land