Spotting

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How it Works: Spotting and Concealment

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.

Detectability range

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 detectability range by sea. A line of sight is required between the spotting aircraft and the ship/aircraft being spotted.

Launching torpedoes, firing AA and secondary guns does not increase a ship's detectability ranges. 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 (when not in a smoke screen) 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). 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.

Fires

A ship that is on fire and not in a smoke screen 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. When a ship is in a smoke screen, fires do not change the detectability ranges.

Floods do not increase a ship's detectability range.

Modules and Commander Skills

A ship's detectability range can be reduced by using the Concealment System Mod. 1 (available in the 3rd modification slot) and some commander skills and base traits. The bonuses from each stack together multiplicatively, so Yukikaze (with a base sea detectability range of 6.6km) when fully decked out for concealment, can have a sea detectability range as low as 4.8km.

Spotting range

Another value is spotting range (sometimes called view range), which is the range inside which other ships might be detected or spotted. 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 darker blue/red icons. The standard spotting range is 20km. It can be increased by 20% by using the Target Acquisition System Mod. 1 (available in the 3rd modification slot).

If a ship has more main battery range than spotting range (which often occurs with russian cruisers), it will still be able to fire at maximum range, but will not see the ships. The player will basically be in a similar situation as if enemy ships were not detected.

Consumables

Smoke

By using a smoke generatora surface ship may create a smoke screen. Not all ships have this consumable, but any ship may enter and use a smoke screen. 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 by ships is the assured detection range (= 2km, see Range of Guaranteed Acquisiton below). However, a ship firing its main battery in smoke increases its detectability range by sea, but to a lower value than without smoke (see Firing Main Guns above). If an enemy ship is present within that range the firing ship will be detected. Hence smoke is not a cloaking device. The detectability range by sea after firing main guns in smoke is higher for ships with larger main gun calibers.

An aircraft cannot detect a ship that is fully inside a smoke screen. In smoke, the detectability range by air is always 0 km, even when firing main guns. However, an aircraft can detect a ship that is on the other side of a smoke screen because smoke screens have a low height.

While a smoke screen obscures the vision of enemy positions, it also obscures the vision of those within the smoke.

Sonar

When active, Sonarautomatically detects ships and torpedoes within a fixed radius, regardless of line of sight.

Surveillance Radar

When active, Surveillance Radarautomatically detects ships within a fixed radius, even those otherwise hidden by line of sight. It does not detect torpedoes. Radar has a longer range than Hydroacoustic Search but is active for a shorter period.

Range of Guaranteed Acquisition

At 2.0km (the assured detection range) a ship will automatically detect another regardless of line of sight, making it possible for ships to be detected even if they are hiding inside a smoke screen or behind terrain. This distance can be increased by 50% (from 2.0km to 3.0km) by using the Target Acquisition System Mod. 1 (available in the 3rd modification slot).

If a ship has the Target Acquisition System module equipped, they will spot the enemy ship once reaching 3.0km. However, if the enemy does not have that module equipped, they will not spot the one that has it until they reach 2.0km.