Here you see a part of the bench:
I can't imagine that sitting on a saddle looks like that [note the angle]:
Sitting on a saddle this way would rip the helmsman's ass when depthcharged next time...
These authentic pics were taken by
Lothar-Günther Buchheim [author of 'Das Boot'] during his patrol on U-96.
I think these saddles in stock SH3 are phantasms of the developers since they couldn't get any docs about the correct seats.