Been looking at someone's drone footage of Amble, on YouTube:
https://www.youtube.com/watch?v=Kfjkj-iBR5I
On the view of the lighter wrecks on the North Side at
4.18 there are rows of circular objects lining the channel on the right of the picture.
(you will probably have to get it to play in HD to see them)
I'm sure it will turn out to be a stupid question but what are they?