I was using them the other day in DsX, had a few issues
they didn't seem to want to target by themselves; i sent them into the opposing sea players base, they would shoot at things but only if their torso was already aligned to target them... clicking and picking targets manually seemed to override this.
also... there seems to be something a bit strange about how they fire, they seem to miss the target quite often underwater (which seems odd especially when you're dealing with stationary units)
cheers!