I am writing a novel that includes a nocturnal U-boat burial at sea.

I plan a few words by the captain over the body wrapped in a Kriegsmarine ensign.

Did the Kriegsmarine also sing "Ich hatt' einen Kameraden" (as the Wehrmacht did)?
If not, would any other song be sung at burial? Would they sing Deutschland über Alles?

Would it be credible to remove the ensign, and submerge with the shrouded, weighted body on deck to be washed away?

Was anything specifically read at such a service?

Any other details to lend authenticity to my fictional account would be greatly appreciated.