Partials/Opening ASW


 * The opening anti-submarine attack (OASW) can be performed by any ship with displayed ASW value of 100 or greater (ship's ASW stat + equipment ASW, not counting equipment improvements) and at least one sonar.
 * Isuzu Kai Ni is an exception and can always perform the opening anti-submarine attack, even with less than 100 displayed ASW or without any ASW equipment.
 * If several ships fulfill the requirements, then they all can perform preemptive attacks, each attacking a random submarine in the enemy fleet. The firing order is determined by the range order, similar to the First Shelling Phase. The order for ships of the same range is random.
 * The damage follows the usual ASW formula and is affected by the usual modifiers (formation, engagement, health, ammo), as well as equipment improvements.

The following table shows how much base ASW is needed (in form of required ship level) to enable OASW with a given equipment setup (T4: Type 4 Passive Sonar, T3: Type 3 Active Sonar, DC: Type 3 Depth Charge Projector).