I've heard and used the phrase since I was a lil' one ... used around the New England seacoast meaning the weather has changed and a cool wind is coming off the sea ... specifically it's a Summertime word used when the weather has been hazy, hot, humid (3H weather) then there is a sea change and the wind comes across the cold ocean waters to cool us all off.

When I read this response, I also thought that maybe the use of the term has legitimately evolved. After all, it's being used by people actually near the ocean, with a vested interest, and a familiarity in the surrounding environment.

So, it seems to me that it could have once been a fresh metaphor, but now is in the doldrums.