Second Edition rules 1. Land units are allowed to land in Western Canada from East Canada Sea Zone 2. Submarines cannot submerge (not enforced) 3. Naval units can't be placed in enemy-occupied sea zones (not enforced) 4. Air units can't retreat from amphibious invasions. Most rules are the same as the World War II Classic game
Destroyers attack and defend at 2, and cost 8 PUs. They have no special antisubmarine capabilities
Marines attack at 1 (2 during amphibious assaults), defend at 2, and cost 4 PUs.

Iron Blitz-2nd Edition