Bigger, warfaring submarines

[Fishface 5]

No explanation needed... Bigger submarines and different classes of them, much like the schooner, brigantine and galleon classes. 

 

Along with it, you could add some anti-sub weapons for ships, like depth-charges and a new device for detecting them... Like a magical/steampunk device that works like sonar

Edited July 23, 2019 by Fishface