Slitherine

This may be intended but may i ask why destroyers cant attack submarines? The same way only 1 fighter can attack a unit at one time

destroyers- like all units, need to be in range at the start of the turn to attack a visible SUB - DD's just don't have range

you can move and sweep or bump into SUB's

But that makes it extremely difficult to attack submarines, Do you have to be in their line of sight to attack them? And yeah how come with air units you can only attack an air unit once ?

those are the rules :-)which work fine really

Fair enough, but may i ask why?

game balance and historical effect