Damage saturation occurs when a ship takes excessive damage to one of its compartments. When a certain amount of damage is inflicted on a compartment, it will be incapable of taking damage exceeding 10% of the shell's listed alpha damage. When a compartment is no longer capable of taking damage above 10% of the shell's listed alpha damage, it has become damage saturated.
Ships are comprised of multiple compartments, including the bow, stern, citadel, casemate, and superstructure. Each of these compartments has a different hit point (HP) pool. There is also a shared "hull" compartment which takes damage whenever a local compartment takes damage.
- Note: Some Battleships and large cruisers may have a second, "upper" casemate which is vertically divided from its regular casemate. There is nothing special about this sectional division except its location.
- Note: Non-French destroyers (and Aigle) have an infinite HP pool in their casemate compartment, and thus it cannot become saturated. Penetrating hits to this compartment will always do full damage.
The maximum HP for these compartments are always 105% of the ship’s maximum HP. The maximum HP of the "hull" compartment is always 75% of the ship's maximum HP. The difference between these two is taken up by the bow, casemate, upper casemate (if it exists), stern, and superstructure according to their total volume. What this means is that larger compartment generally contain more HP.
When a shell fully penetrates and damages a compartment, its damage is divided between the local compartment and the "hull" compartment. Shells which penetrate the citadel will not divide their damage. Overpenetrating hits will apply damage to the ship, but not to any compartment (this includes the "hull" compartment).
If an Armor-Piercing (AP) shell fully penetrates, the compartment it damages will be the one where the shell exploded. This may be different from the compartment where the shell initially entered the ship, in the case of oblique hits or long fuze times.
If a High-Explosive (HE) shell fully penetrates, the compartment it damages will be the one it initially contacted. Many ships have torpedo bulges which are not part of any compartment, and penetrating hits to these will not inflict damage on the ship nor any compartment.
For example: An AP shell from Yamato has a nominal damage of 14,800. A penetrating hit on the citadel of another ship will do exactly that - 14,800 damage. A fully penetrating hit to the casemate of another ship will do 4,884 (0.33x) damage before saturation. 2,442 (0.165x) of this damage will be applied to the local casemate compartment. Another 2,442 (0.165x) of this damage will be applied to the "hull" compartment. If either of these compartments do not have enough HP, the damage will be reduced by the difference.
Compartments, not including the citadel, have two thresholds. When the damage thresholds are reached, incoming damage will be reduced.
First Damage Threshold (Local Saturation)
When the first damage threshold is reached in a compartment, damage values are halved. At this stage, penetrating shells will do only 0.165x damage, all of it directed to the "hull" compartment. This effect occurs because the local compartment has had its HP reduced to 0. This stage can be identified by the appearance of visual blackening of the compartment.
Second Damage Threshold ("Full" Saturation)
When the second damage threshold is reached in a compartment, shell penetration damage is reduced to 10%. This is because the "hull" compartment has been completely depleted of HP. There is no visual difference between the first and second threshold, but shells will no longer inflict damage above the 10% mark.
If the "hull" compartment has been drained of HP, then hits to an undamaged compartment will do only 0.165x damage, even if that compartment has not yet been hit by a shell.
Full penetrations of the citadel will always do 1.0x damage, regardless of the saturation status of the hull or other compartment.
Fire, Flooding, Ramming, Overpenetration & Citadel Hits
Damage from fire, flooding, ramming, overpenetration, and citadel hits will not reduce any specific compartment’s HP pool. Rather, these only affect the total HP pool of the ship. A compartment with no HP remaining may still burn or flood normally and continue dealing damage to the ship.
Tips & Recommendations
It is recommended that players be mindful of damage saturation when attacking an enemy ship. When firing at a ship's superstructure, watch for visual blackening, as shell penetrations will no longer be inflicting maximum potential damage. If shells stop inflicting damage completely, alter aim to focus on a different compartment.