Once a player has assigned ships into task forces, a player with subs in the same sea zone may choose to have the subs attack any number of task forces. A sub may intercept and attack any task force moving into or out of the sea zone the submarines are in or attempting to offload a transport into a territory adjacent to the sea zone the subs are in. Task forces which are doing none of these things may not be targeted by subs for interception.
--Example:
Using the example above, let us say the German player had 4 subs in sea zone B. He could send subs to intercept task forces A, B and C but not D. He decides that going after C is too risky, but task forces A and B make tempting targets. He sends 2 subs against the 1 destroyer in task force B, fairly certain of success. He sends the remaining 2 subs against task force C, not because the odds suggest total victory, but because with a decent luck will cause the British player to lose either a battleship or the loaded transport and the destroyer. Either outcome will mark a small economic victory for the Germany U-boat navy.
Combats that arise from sub interception are fought as usual with the following exceptions. If the attacking subs attempt to retreat the combat ends but the surviving subs remain in the sea zone. The intercepting subs cannot retreat if aircraft are assigned to the naval task force, but once the aircraft are forced to return to land (due to lack of fuel points), then the subs may retreat as usual.
