- 1 Detectability range
- 2 Spotting range
- 3 Consumables
- 4 Proximity spotting
- 5 Torpedoes
- 6 Radio Position Finding
- 7 Situational Awareness
- 8 Thunderstorm Fronts
- 9 Notes
A ship or aircraft is detected or 'spotted' when an enemy ship or aircraft gets close enough to detect it, and if necessary for the type of detection, has line of sight (LoS) to it. An enemy that is spotted can be targeted for destruction.
The most important value is detectability range, which is divided into two categories:
- Detectability Range by Sea (surface detectability range): This is the range at which a ship or aircraft will be detected by an enemy ship. A Line of Sight (LoS) is required between the spotting ship and the ship/aircraft being spotted. A ship will not be spotted by an enemy ship if there are no enemy ships within this range.
- Detectability Range by Air (air detectability range): This is the range at which a ship or aircraft will be detected by an enemy aircraft. For ships, this is usually shorter than the detectablity range by sea. A line of sight is required between the spotting aircraft and the ship/aircraft being spotted.
Attack aircraft, bombers and torpedo bombers usually have a detectability range (both by sea and by air) of 10 km (Japanese torpedo bombers: 7.5 km).
Launching torpedoes or firing secondary guns will not increase a ship's detectability range. Sailing slowly or stopping completely will not reduce a ship's detectability.
There is a period of guaranteed acquisition: if a ship is detected by an opponent, it will remain visible to the enemy for at least 2 seconds. This prevents an enemy ship from "flickering" at the edge of the line of sight—i.e. appearing and disappearing from the map in rapid succession.
As a result, if your ship leaves an opponent's line of sight 1 second after you were detected, you'll continue to be visible to the enemy ship for a further 1 second. However, if your ship was visible to the enemy ship for 2 seconds before leaving the enemy ship's line of sight, you'll disappear from the enemy's view immediately.
Firing main guns
Firing main guns will increase sea detectability ("bloom") to the current maximum range of the main guns. Air detectability will also increase by a smaller amount depending on the ship (and it is possible in this situation for air detectability range to exceed sea detectability, e.g König). If the ship is detected because of the bloom, detectability will reset after 20 seconds. However, if the ship leaves the enemy's line of sight (e.g. by hiding behind an island), detectability will reset 2 seconds after that. If the ship remains undetected at the moment of the bloom, it will reset immediately.
Sometimes you can shoot over an island at an enemy (who is spotted by your team) and stay undetected.
Firing AA guns
Firing AA guns will increase air detectability (but not sea detectability) by an amount depending on the ship. The detectability range by air is equal to the firing range of the ship's AA guns for a period of two seconds after her AA guns cease firing. This affects detectability only in situations where enemy aircraft are within the range of your AA defenses.
AA guns can be toggled with the P key.
A ship that is on fire will have 2 km added to its sea detectability range and 3 km to its air detectability range for as long as it is on fire. The increase does not stack with multiple fires.
Upgrades, skills, camouflage
A ship's detectability range can be decreased by using certain upgrades, skills and camouflage. The bonuses from each stack together, so a Kagero (with base sea detectability range of 6.84 km), when fully decked out for concealment, can have a sea detectability range as low as 5.37 km.
Another value is spotting range (sometimes called view range), which also doubles as a ship's render/targeting range. This is the range inside which other ships might be detected or spotted. It is indicated visually by the outer limit of the grey cone on the player's minimap in battle. No ship outside of this range can be detected by the player. Allied ships and enemy ships spotted by others that are outside of view range are not drawn on the main screen but are displayed on the minimap as outlined icons.
In general, the taller the ship the larger its view range. Battleships with their tall masts have very long view ranges (in excess of 20 km) while destroyers typically have the shortest view ranges. All aircraft have a view range of 15 km.
Generally, view range has little impact on ship to ship detection because it is usually higher than the detectability range of the ships being spotted. The only time view range limits ship to ship detection is when the spotting ship has a lower view range than the target's detectability range, such as a destroyer attempting to spot a battleship. In these cases, the target is spotted not at its detectability range but when it enters the view range of the spotting ship.
Cyclones reduce spotting range for all ships on the map. At full effect it is limited to 8 km. Radar increases spotting range (to the same value as radar range) for its duration during cyclones but only for the ship using the radar.
In the diagram to the right, assuming that all ships are enemies to one another, the destroyer (pink) can detect the cruiser (orange) as the cruiser is within the destroyer's view range (pink dashed line) and the distance between the two ships is smaller than than the cruiser's detectability range (orange line). However, the destroyer can not detect the battleship (blue) even though the distance between them is smaller than the battleship's detectability range (blue line) because the battleship is outside of the destroyer's view range (pink dashed line).
The cruiser on the other hand can detect the battleship, as it is within the cruiser's view range and the distance between them is smaller than the battleship's detectability range, however the cruiser can not detect the destroyer even though it is within the cruiser's view range because the distance between them is larger than the DD's detectability range.
The battleship can not detect either the destroyer or the cruiser even though the battleship's view range encompasses both of them because their distance to the battleship is larger than their respective detectability range.
If the destroyer and the battleship are on the same team while the cruiser is on the opposing team, the destroyer will spot the cruiser for the battleship and it will appear as a solid icon on the battleship's minimap and be rendered in its main view. If the destroyer and the cruiser are on the same team while the battleship is on the opposing team, the cruiser will spot the battleship for the destroyer but it will only appear as an outline in the destroyer's minimap and not rendered in its main view.
Smoke blocks line of sight (LoS). If a ship is inside a smoke screen or has smoke between it and all possible spotters, it can remain undetected even when there are enemy spotters within its normal detectability range.
Usually, the distance at which a ship covered by smoke can be spotted is the assured detection range (see Proximity Spotting below). However, a ship firing its main battery increases its detectability range considerably (see Firing Main Guns above), even when firing from smoke. If an enemy ship is present within that range the firing ship will be detected. Hence smoke is not a cloaking device.
For air detection, the smoke cloud is considered to be at the same height as the aircraft. Therefore, an aircraft must be close to or over the smoke screen in order to detect ships hiding beyond it. However, an aircraft can not detect a ship that is fully inside a smoke screen.
While a smoke screen obscures the vision of enemy positions, it also obscures the vision of those within the smoke. See the smoke screens article for details.
When active, Hydroacoustic Search () automatically detects ships and torpedoes within a fixed radius, regardless of LoS.
When active, Surveillance Radar () automatically detects ships within a fixed radius, even those otherwise hidden by LoS. It does not detect torpedoes.
Radar has a longer range than Hydroacoustic Search but is active for a shorter period. Some Surveillance Radars can detect only certain types of ships (e.g. Russian battleship radar will detect only large ships -- aircraft carriers and other battleships).
At 2 km (the assured detection range) a ship will automatically detect another regardless of LoS, making it possible for ships to be detected even if they are hiding inside a smoke screen or behind terrain.
Some ships incorporate elaborate torpedo protection schemes. However, the best protection against torpedoes is not to be hit by one in the first place. Detecting an incoming torpedo far from the ship gives the bridge crew time to maneuver to avoid it. Aware of this, torpedo designers try to make their fish as hard to spot as possible. One technique is to have the torpedo run deep — the notorious heavyweight deep water torpedo with a natural detection range of <<1km.
Unmodified ships spot torpedoes from a range based on the torpedo model from 0.7km to 2.5km.
Ship-Launched Torpedo Specifications
The Torpedo Lookout System () (TLS) upgrade detects torpedoes independent of model and is very effective against low-detectable torpedoes. It assures detection of all torpedoes within a base 1.8 km distance.
The Vigilance skill extends torpedo detection range 25%, with or without TLS. These are both essentially passive mechanisms.
The Hydroacoustic Search () consumable, while it is active, detects torpedoes at an even greater distance. The actual range depends on the ship, varying from 2.5 to 4km.
Once a torpedo has been spotted, it remains spotted for the duration of its run.
Radio Position Finding
The Radio Location skill displays a white marker indicating the approximate (22.5 degree sector) direction -- but not distance -- to the nearest enemy ship. That ship will be notified that it is being tracked through the appearance of a Situational Awareness icon.
Formerly a commander skill, Situational Awareness is now a standard feature of the game. When you are detected by an enemy there will be an icon informing you of the fact. It will also show the type of detection:
- Visual/proximity by sea
- By Hydroacoustic Search or Surveillance Radar
- By air
- Radio Position Finding
If you are detected by multiple means only the highest in the list will be displayed.
Thunderstorm Fronts reduce the ship's detectability range by sea and the 20 seconds, and limit the spotting range.