Only two effects have a chance to cause a ship to flood:
It is impossible to cause a flooding on an allied ship.
A ribbon is awarded when a flood is caused to an enemy ship. Though captains may be awarded multiple flooding ribbons, it is not possible for a ship to suffer from the effects of more than two floods concurrently: one forward and one aft. This is distinctly different from fires, where a ship can suffer from up to four simultaneous fires that stack their damage-over-time effects together.
The probability of a ship flooding depends on where it is struck by the torpedo (or rammed by the enemy ship), the presence of upgrades on the damaged ship (specifically, Damage Control System Modification 1), and the signals mounted on the attacking ship: Juliet Whiskey Unaone () increases the chance of causing a flood by 15%; Victor Lima () increases it by 4%.
All ships — except destroyers — have torpedo protection for their citadel. As a result, the chance of flooding and damage are reduced even if the ship doesn't have "Torpedo Protection" displayed on the Port screen. Destroyers do not have any torpedo protection, and the torpedo damage reduction bonus of Damage Control System Modification 1 () will not work properly when the upgrade is mounted on a destroyer..
In order to calculate the flood chance of a given torpedo versus a given ship, the following formula is utilized:
- The value of "Torpedo Protection" varies by ship and is displayed in the Port screen.
- The value of "DCM1" is 0.03 if the appropriate upgrade is installed; otherwise, it is 0.
- "Torpedo Flood Chance" values can be found in the tables below.
Ship-Launched Torpedo Data
Aerial Torpedo Data
Aircraft carriers, destroyers, and cruisers take 0.25% hit points of damage per second per flood; battleships and large cruisers take 0.5% hit points of damage per second per flood; and Admiral Graf Spee takes 0.375% hit points of damage per second per flood.
Flooding has a base duration of 30 seconds for carriers and 40 seconds for the other classes. A full duration flood deals a higher percentage of the total health pool in damage than a full duration fire (2 percentage points more on battleships and large cruisers, 1 more on cruisers and destroyers, 2.5 more on aircraft carriers).
In addition, ships that are flooding have their top speed reduced by 30% at full speed forward, and 60% at reverse.
The effects of flooding can only be removed by utilization of the Damage Control Party () consumable, or by waiting for the flood duration timer to expire. There are two sections of the ship that can take floods: one forward and one aft. Flooding duration can be reduced several ways:
- Equipping Damage Control Modification 2 will reduce the duration by 15%.
- Using a commander with the Level 3 commander skill Basics of Survivability will reduce the duration by 15%.
- Flying the Juliet Yankee Bissotwo signal () will reduce the duration by 20%.
Each of these effects stacks with the others; however, they are multiplicative rather than cumulative.
For example, if all three effects are stacked, the flooding duration is: 40 seconds x 0.85 x 0.85 x 0.80 = 23.12 seconds.
The below table provides the flood durations and total health loss for the different combinations of the above three effects.
|Total damage||7.5% of base health||30 seconds|
|With one -15% modifier||6.25% of base health||25 seconds|
|With a -20% modifier||6.0% of base health||24 seconds|
|With two -15% modifiers||5.25% of base health||21 seconds|
|With one -15% modifier and a -20% modifier||5.0% of base health||20 seconds|
|With two -15% modifiers and a -20% modifier||4.25% of base health||17 seconds|
|Total damage||20.0% of base health||40 seconds|
|With one -15% modifier||17.0% of base health||34 seconds|
|With a -20% modifier||16.0% of base health||32 seconds|
|With two -15% modifiers||14.0% of base health||28 seconds|
|With one -15% modifier and a -20% modifier||13.5% of base health||27 seconds|
|With two -15% modifiers and a -20% modifier||11.5% of base health||23 seconds|
|Total damage||15.0% of base health||40 seconds|
|With one -15% modifier||12.75% of base health||34 seconds|
|With a -20% modifier||12.0% of base health||32 seconds|
|With two -15% modifiers||10.5% of base health||28 seconds|
|With one -15% modifier and a -20% modifier||10.125% of base health||27 seconds|
|With two -15% modifiers and a -20% modifier||8.625% of base health||23 seconds|
|Total damage||10.0% of base health||40 seconds|
|With one -15% modifier||8.5% of base health||34 seconds|
|With a -20% modifier||8.0% of base health||32 seconds|
|With two -15% modifiers||7.0% of base health||28 seconds|
|With one -15% modifier and a -20% modifier||6.75% of base health||27 seconds|
|With two -15% modifiers and a -20% modifier||5.75% of base health||23 seconds|
All damage sustained by flooding is 100% recoverable by ships that can use the Repair Party () consumable.
- Update 0.7.6.
- This group includes Tier IX Alaska, Alaska B, Azuma, and Kronshtadt, and Tier X Puerto Rico, Yoshino, and Stalingrad.