Sea Rocket
There’s Sea Rocket, Cakile maritima, on the beach at the Bay of Swartmill.

It’s a member of the mustard family.
This is my post from 2015 saying I really must try eating it:
This is my post from 2017 saying I really must try eating it:
Here we are in 2019.

On Westray it’s a sparkling jewel on the sandy beaches, with its chunky stems and glorious white or lilac flowers. Elsewhere in the world where people have introduced it, it’s classified as a noxious weed. That’s what happens when you knock nature out of balance and remove a single species from its complex interrelationships with pollinators and predators.

I try eating it.
It tastes mustardy.