I worked in the Radio Centre at Chatham Dockyard after leaving college in the 1960's, Valiant and Warspite were the two nuclear sumarines undergoing refits while I was there.
Amazingly, there are certain hazards to sailing under the surface.
Some key components of the power system used to carry very hot fluids around were susceptible to corrosion.... surprising, that, I mean it's only salty water outside....
End result was a series of 'bodges' to keep outside water at high pressure in the place where it belonged... outside.
High tech gaffer tape was used, Captain was told it would be okay to about 50 feet or thereabouts....
I'm not kidding!!!!
HMS Diamond (destroyer) was sold to a foreign power (African?) and had a bit of a spruce up before departing.... it never arrived as far as I know!
One technician dropped a spanner on deck, and was aghast at its disappearance through a brown biscuit like material covered in grey paint....
There's an aviation link here too, the early radar controlled turrets were a little temperamental, and while tracking an obliging Hunter they resembled a pensioner sans white stick and guide dog. Sort of indecisive and doddery!
1940's technology continued into the 70's and 80's, the four ships we sold to Argentina were not capable of joined up warfare due to a lack of spares... ditto some of the British ships, identical in specification!
Hi fi enthusiasts will know about old fashioned glass cased radio components... made by ancient craftsmen... imagine two rooms of these doing the same job as a mobile phone app.... warm was good sometimes!