I wanted to propose an idea to simulate naval fog of war into the game. The ability to detect and determine enemy location and strength was often critical during WWII. This was especially true for both the Battle of the Atlantic and the massive naval engagements in the Pacific. This game as well as many other WWII games, eliminates the fog of war by placing all units with their exact composition and location on the map.
My proposal is to use hidden task force markers. The top side of the marker would have the national symbol or flag while the flip side would have a number on it. These markers would be put on the map in place of the naval units. On a card kept off the map would be a card with a matching number and the naval units within that task force.
Whenever one side completes its movement, naval combat would need to be resolved in all the sea areas that contain task force markers from opposing sides that are at war. The identity and composition of the naval task forces would then be revealed when resolving naval combat.
Another option would be to allow active players to use aircraft units within their tactical ranges to perform recon missions to sea areas to discover the composition of an enemy naval task force. Each naval task force would have to include at least one naval unit.
The naval units of neutral nations such as the US would not be hidden until they are at war.
This would add a fog of war element to the naval element of the game without adding too much complexity. This should perhaps be an optional rule used by players that have a fair level of experience with the game. Most of all, this could provide the game with some exciting naval strategy opportunities and battles!