An expansion/overhaul mod of epic proportions, with entirely rebalanced gameplay, expanded factions, new gametypes, graphical overhauls, and five new factions; stealth-based Confederate Revolutionaries, tower defense-inspired Atomic Kingdom of China, economy-focused Mediterranean Syndicate, DotA-esque Order of the Talon and spammy Electrical Protectorate.
The Subhunter Frigate originated as a ocean-going cruise ship that, due to high-powered engines and copious internal space was pressed into service as a "Q-ship"; appearing unarmed, it would lure a Soviet Submarine to surfacing for an attack, then retaliate with torpedoes of its own. So successful was it at this role that the design was reborn as a dedicated warship towards the end of the war, the excess weight lost and significantly upgunned. Partnered with an Assault Destroyer it makes a deadly combo; though the weak armour of the Subhunter Frigate cannot stand up to enemy attacks it can dish out impressive damage, while the Assault Destroyer can draw enemy fire. In addition, the Subhunters secondary depth charge torpedo slows and damages enemy unis and forces enemy submarines to surface.
Will this be better than the Assault Destroyer?
Not better so much as complimentary. The Assault Destroyer is high-armour, low damage, the Subhunter is high-damage, low armour. Between the two they can do a lot of damage.
These can attack all sea units? Not just under water ones?
Sure he can he is attacking the building which is not under water one...
obviously... it`s a torpedo boat, you could compare it to the naginata.
Will it be stronger than the naginata?
No, overall the Naginata is a superior design. Though the Subhunter does slightly more DPS, it's armour is very, very much inferior.