You mean like the Hedgehog launchers?
Lets see roughly 800 damage per explosive, you fire 7 at a time with the premium ones (Which are free atm)
so 7x800=5600 Dmg. per launcher if you were to hit all of them pretty much. so.. oh yeah they can be effective against large ships, even though their meant for Anti-Sub uses.
1st problem. Do you think the large ship is going to let you get close enough?
2nd problem. They take like 30 seconds to reload. lol.