"off the sea" is correct and can be used in written English.
It is a prepositional phrase and can be used to indicate direction or location. For example, "We watched the sunset from the cliffs off the sea."
Nearly everyone in the town and in the surrounding villages lives off the sea.
They are faint implications now, a hiatus disappearing against the light off the sea.
It was December and a frigid wind was blowing off the Sea of Japan.
For example, 5km of derelict port cut off the sea from the rest of the city.
In this city that lives off the sea, people know about disaster.
A blustery wind was blowing off the sea and up the Aeron Valley as we set off.
The Netherlands has the resources to wall off the sea, but what about other parts of the world?
Millions of Indonesians live off the sea, mainly from fishing, while much of the vast archipelago's trade moves by sea.
Waiting was never so easy: you swim off the sea walls, picnic and shift the car when need be.
The title comes from the effect on his vision of prolonged exposure to the suffused sunlight coming off the sea.
(Don't even think about Lyme Regis. Louisa Musgrove tried it in Persuasion and – oh, shucks – fell off the sea wall).
