I do not live by the sea, but calomogrostis, "Karl Foerster" does well where I live in zone 6. It gets pounded by salt where I work due to snow removal and has done well. Beautiful plant! Early seedheads (now) which sway in the slightest wind adding movement to your garden. It is also called feather reed grass. It reaches roughly 5 feet tall here with seedheads. Another grass, Little Bluestem has also done very well here. It gets about 2' tall and tolerates drought as well. ( Most grasses tolerate these conditions up here, in my experience,) Good luck!

Blue Lyme grass also tolerate salt very well, but I am told it can be invasive. It actually made the top 5 of a study on salt tolerant plants by a woman seeking her masters in Ohio. I would be careful where I planted it, and only do so after further research.