User blog comment:FlammeumDraco333/Tales From the Not so Blocky Seas/@comment-24903406-20150802211244/@comment-27797576-20150803125355

Subs are all in all pretty decent. The US subs will probably be a good choice, as they can go underwater for longer periods of time than most other subs in the other nations. They also are rather fast, as my current S-class can go 21kts. The O-class does around 18kts, give or take 1 kts