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British seamine "northsea relic"


Well-Known Member
Hi All,

Some friends of mine discouvered this piece of
a British seamine.
And the main question is , what type mine it comes from.
Pics of stamps in this post!

ps, Further info is so welcome!
Who makes my day? :biggrin:


This is the mechanism plate of a Britisch mine.The small hole is for the detonator holder.The big hole is for the mooring spindle.

Last edited:
I think a H II Mk II type.

Hi taucher,

ill post some more pics tonight,
i think the sealing-ring gives more info.
got a pic of the mine?

in german>

Hallo taucher,

ich werde heute nog einiges hier an Bilder zupacken.
vieleicht gibt die Gummy-dichtung mehr info.
gibts ein bild von die Mine?

Thanks in advance!

Gruesse aus Holland!
you can even speak Dutch to me but for al of the forum members whe use Englisch.
Groeten vanwege een zuiderbuur.
Here she is.


I wil try to post some more later.

Hi Vince,
thanks for your reply!
this pic is the opposite site of the piece i posted?
do you have one were my piece is vissible?

Many Thanks!
Yes, this is the top plate.Wil post the technical data but have to scan them in.I do not have a clear picture of the mechanism plate of a HII mine.I see what i can do.
Where(position) did your friend found this in the Northsea?

Sea Mine;

Your very fine object is the mooring base plate for a moored mine.
Unfortunately my references as to model is back home in Virginia.
Best I can offer for now.
John aka Bart

The HII came into service in the Britisch navy in 1917.Stocks where still in use during WWII.


What do you think 5-17 stands for.That is your date!The arrow is from Britisch laboratory and is a acceptance stamp.