Detection range mechanics are some of the most important to learn in this game. Read it, learn it and it will make the game more pleasant for you to play. Then you might rethink what you wrote. Not trying to be a turd here, just saying.
The detectability range is the distance at which a ship or aircraft will be detected by an enemy ship. Once your opponents find themselves within your detectability range, an icon pops up to notify that you have been spotted. As soon as you put enough distance between you, or if the enemy leaves your detectability range by themselves, your ship becomes invisible to them again. A ship's detectability range can be decreased by using certain upgrades, skills, and camouflage.
The viewing range is the maximum distance at which your ship or aircraft can spot opponents.
The gray sector on the Minimap displays the viewing angle of your camera in the game. Its furthest border is the edge of your viewing range. In general, the taller the ship, the further its viewing range. Battleships, with their tall masts, have very long view ranges (in excess of 20 km), while destroyers typically have the shortest view ranges. Carriers mainly spot with their planes, which also have a set viewing range.
Through use of the Smoke Generator consumable, a ship creates a smoke screen. Not all ships have this consumable, but any ship may enter and use a smoke screen, even if it was laid by the enemy. All line of sight through the smoke screen is blocked, including your own. You will not be spotted by enemy aircraft when you are inside the smoke screen either.
However, once a ship concealed by smoke starts firing her main battery guns, her detectability range increases considerably. If an enemy ship is present within that range, the ship that is firing will be detected, regardless of the smoke.
A smoke screen does one thing: it obscures vision, preventing those outside of the smoke from seeing into or past it. This effect applies equally to ships inside a smoke screen: a ship in smoke can target an opponent at range, but it requires an allied ship to spot it for her.
Discharged smoke will work for both allied and enemy ships. Do not let the enemy team take advantage of a smoke screen that you have created!
If your ship is within a 2 km range of any opponent, the enemy will detect you regardless of any obstacles—including a smoke screen.
A ship sitting quietly in smoke is invisible outside that 2 km range (barring the use of Radar or Hydro). However, when she fires her main batteries, her detection range increases—although not as much as when firing out in the open. If no enemy detects the ship that is firing from smoke, the range immediately drops back to the non-firing detection range.
If an enemy ship does detect it, the ship remains in a spotted state for at least 20 seconds before the range reverts back to the non-firing detection range. Of course, firing again resets the 20 second timer.
Taken from here https://worldofwarships.com/en/content/education/tactical/
WGing vid on spotting https://www.youtube.com/watch?v=OgRUSmzcw2s