Anyone know how often submarines or U-Boats would have been repainted?

[tricksor]

Curious

[KizmeRD]

There wouldn’t have been any routine maintenance periods scheduled purely for reasons of cosmetic appearance during wartime, as it wasn’t high up on the list of priorities. However if a particular U-boat needed to return to a shipyard say for a larger calibre deck gun to be fitted, or to have structural or mechanical damage repaired, then I’m sure the yard would have taken the opportunity to send them back to sea again with a new lick of paint. 
MB
 

[tricksor]

12 minutes ago, KizmeRD said:

There wouldn’t have been any routine maintenance periods scheduled purely for reasons of cosmetic appearance during wartime, as it wasn’t high up on the list of priorities. However if a particular U-boat needed to return to a shipyard say for a larger calibre deck gun to be fitted, or to have structural or mechanical damage repaired, then I’m sure the yard would have taken the opportunity to send them back to sea again with a new lick of paint. 
MB
 

I see thank you

[James A Pratt III]

Watching some USN ships in peacetime when in port and there were rust spots on the hull someone would be painting them. I would say with submarines and U-boats if the boat was in port between patrols someone would be painting any rust spots ect.

From what I have read about ships mostly in WW II and the were being heavily used like NWA escorts they would look worn and rusty ect.