During World War II, the Western Approaches Command had a secret training center in Greenock, Scotland.
After capturing U-110, a mockup of the boat was built in wood inside a secure building. Boarding parties were trained on this mockup.
Getting familiar with a sub's layout could be vital in getting in and out. Some sailors were trapped and drowned when the sub foundered quickly.
The USS Wilkes was in England after escorting a convoy. They received orders to send a party of five men to
greenock for special training.
They were shocked at finding the Uboat mockup. One of the five was to be an engineer, who got some training on starting the german diesels, besides looking for scuttling charges and securing any valves that would allow water into the boat.
"These things must be done delicately-- or you hurt the spell." - The Wicked Witch of the West.
"We've got the torpedo damage temporarily shored up, the fires out and soon will have the ship back on an even keel. But I would suggest, sir, that if you have to take any more torpedoes, you take 'em on the starboard side." Pops Healy, DCA USS Lexington.