Pssssst.....
I'd go for the last option mentioned by Steamwake.

I read a story in a US Submarine Veterans quarterly ( cant recall the name ) where a the crew of a crippled submarine patched together a sail and stringed it up with a periscope mast. It was a dismal failure because they were fighting with tide and predominant winds.

Eventually a Jap destroyer forced them to surrender, I believe the sub was scuttled.

Does'nt help you here but I thought it was an interesting anyway.

Slap on the suntan. :sunny:

This needs a mod. Since the port/starboard screws thing is likely not possible, I'd go with making the rudder indestructible. Perhaps there is a way to have it damaged so that it functions less well, but always functions at some level.

Sorta like there should be one indestructible diesel since fleet boats had 4 plus a charging engine, wrecking all so that none could be fixed with parts from the others is so unlikely as to be impossible.