[wally_bert]

Didn’t the Germans do that in WW II to refuel the U Boats?

[Brian Griffin]

They apparently tried, but by mid-1943 the U-boats of every type were being sunk readily:

https://www.quora.com/How-did-the-German-U-boats-of-WW2-carry-enough-fuel-to-make-it-to-the-east-coast-of-the-US-and-back-to-Germany-Did-they-have-a-way-to-refuel

“The Type IXB Uboat that was used off the east coast of the USA had a range of about 14,000 miles at about 12 mph on the surface.”