In SC, the open sea is divided into smaller Sea Zones. The naval units can then be located in a Sea Zone, or a port or an all-sea hex assisting an Amphibious Invasion. It is important to note that they do not move like ground units on the map. The hex they can occupy are clearly restricted to the ones mentioned above.
However, main naval combat only occurs during the Strategic Naval Combat Phase. here, both players locate naval units into Sea Zones to prevent transportation operations by the enemy forces.If both sides have fleets in the same sea zone, they can contest/fight for the control of the particular sea zone and initiate naval surface combat. Each side totals its strength as the sum of the Surface fleets and tech bonus. Each side rolls a dice on the Naval and Air Combat Table using the appropriate column related to its strength versus the enemy strength to determine the final result. The result can be “no effect”, “abort operation”, “HIT” which indicates that one fleet is eliminated.
It is worth noticing that there is also submarine fleets in SC. In USE the submarine warfare is much more abstracted but still well-represented. Here, we can have also surface vs. Sub. Combats.
Regarding the Air Force movement and combat, we can distinguish between the regular phase and strategic phase. Friendly controlled ports, cities or capitals can function as Air Bases. The range from combat can be traced from an Air Base is 3 hexes plus technology bonus for Fighters and 5 hexes plus technology bonus for Bombers.
For Strategic Bombardment the attacker places available in-range units that are planned to be used against a target hex, which should be an enemy-controlled MSP. The defender may then try to intercept to the Target Hex with any in-range fighter units. When both air fleets include fighters, the fighter combat is solved first, but computing the different of strengths including technology bonus. Surviving bomber units can then be hit by flak unit. If still bomber units survive they can finally attack the target hex.
In normal movement phase, the air units can be moved from one Front Air box to another. Those units that do not participated in the strategic phase, can then be used in the movement phase. The objective in this phase is to perform Ground Support Attacks. Therefore, once a target hex has been determined attacker can use any in-range bombers escorted by fighters to attack the hex. The defender may do the same so the combat between fighter escorts is resolved in a similar way than that in the strategy phase. The surviving bombers may still face flak defensive attacks. Finally, if at least one bomber unit still survive may provide ground a support to the ground attack. As we can see the mechanics is a bit more elaborated than that of USE, but still both can play a good role in each game context.