"tho I believe there is one or two surface ships that this does not apply to? "

In situations where your engineers are good enough to handle less horsepower to compensate
for the extra weight the better engine has.

Pensacola/Moltke are faster with CV engines at first but with a fatter crew and good
engineers the CA engine becomes the better choice. H39 is similar with BB/PS/BC engine

Hmm... I don't think there are many options for the SS1. He's probably having great
difficulty since all SS1's kinda suck.

Best advice I can give you man is to level a planesman, sonarman, and 2 torpedomen.
Maybe a restorer/repairer and some engineers will help. However this biggest difficulty
I'm sure you're having is the fact that SS1's have to be played completely differently
than other subs. Ponder the word defensive as much as possible when driving it. You'll
either get to attack something or survive (team win) every time.

solid advice given...Heavy Engine is usually the best in most cases... In some cases
(other than SS) there is a better option than that of the norm Heavy. Look for the most HP
generally..tho I believe there is one or two surface ships that this does not apply to?

SS heavy engine
SS1 FCS