I thought submarines fire first in combat as part of their special abilities...meaning it's useless to attack them with airplanes, since they'll retreat before you get the chance to roll any die...am I being wrong about something?
Great question! Yes, IF submarines are the only unit type in an attacking force, they DO fire first (the "first strike" capability). However, it's ONLY against enemy ships, not planes. In lieu of that attack, they cannot instead move or submerge. It's an attack-only first strike.