I ran across this interesting press image and thought you guys would enjoy it.  The caption reads:

 

”Island Forts” Protect British Shipping, 2/2/1944. On the British Coast – Manned by Royal Marines, “Island Forts” like this one are protecting Britain’s east coast. Each fort consists of two concrete towers, 50 feet high, connected by a superstructure on which ack-ack guns and equipment are mounted. Commissioned as H.M. ships, the forts have accounted for a number of German aircraft. Credit: ACME.

 

Frankly, I have never heard of these "forts" before.  I wonder if any of them are still around?  Looks like poured concrete so they should be pretty tough.  Sort of like the German Flak Towers in Berlin.

 

 

They are there although gradually degrading.

 

If you want to find out more you start here:-

 

https://en.wikipedia.org/wiki/Maunsell_Forts

 

I did a Google search, the results page will show you lots more information.

 

https://www.google.com/search?q=maunsell+sea+forts&rlz=1C1CHBF_en-GBGB826GB826&oq=maunsell+sea+forts&gs_lcrp=EgZjaHJvbWUyBggAEEUYOdIBCDgzODVqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8

 

I saw them in the 1960's when I was taken on a boat trip by my parents.

 

 

 

Thank you for the link and additional information, Richie.  Most helpful and fills in the considerable gap in my knowledge.  Your links establish that these particular types of sea forts were known as "Maunsell Naval Forts".

 

This proves yet again why WW2 remains such a fascinating subject.  It is boundless and there is always something new to learn.

 

Regards,

Charlie