Smoke Screens

Revision as of 21:23, 16 November 2019

Smoke screens are created by smoke screen generators on ships. In game these are represented by smoke generator consumables.

Most destroyers and some cruisers mount one.

——  Smoke Generators of the World  ——  (click here)

A smoke generator produces smoke 'puffs' at regular intervals that merge to form the smoke cloud or screen. All smoke has the same concealment effects but can vary in other characteristics:

• Radius - the size of a puff. (Puffs overlap.)
• Emission time - the length of time the generator runs, producing new smoke puffs. (also called 'Action time')
• Dispersion time - the length of time each puff lasts before dissipating.

					SMOKE GENERATOR
Class or Ship	Tier	Nation(s)	Radius	Emission Time	Dispersion Time	Cooldown	Charges
Iwaki Alpha	IV		0.45 km	15 seconds	80 seconds	160 seconds	3
Chikuma II	IX		0.45 km	20 seconds	93 seconds	180 seconds	3
Flint	VII		0.45 km	30 seconds	121 seconds	160 seconds	3
Anchorage, Rochester	VIII		0.45 km	30 seconds	104 seconds	160 seconds	2
Wiesbaden	VIII		0.45 km	15 seconds	69 seconds	180 seconds	3
Mikhail Kutuzov	VIII		0.45 km	20 seconds	89 seconds	160 seconds	2
Smolensk	X		0.45 km	20 seconds	89 seconds	160 seconds	2
Emerald, Leander, Fiji, Gibraltar	V - VII, X		0.60 km	15 seconds	96 seconds	160 seconds	3
Belfast	VII		0.60 km	15 seconds	103 seconds	160 seconds	3
Tiger '59	VIII		0.60 km	15 seconds	106 seconds	160 seconds	3
London, Edinburgh, STAR Edinburgh	VI, VIII		0.60 km	15 seconds	99 seconds	160 seconds	3
Neptune	IX		0.60 km	15 seconds	110 seconds	160 seconds	3
Minotaur, Plymouth	X		0.60 km	15 seconds	113 seconds	160 seconds	3
Edgar	XI		0.60 km	15 seconds	120 seconds	160 seconds	3
Cruisers	II - X		0.45 km	30 seconds	70 seconds	110 seconds	3
Dalian	IX		0.45 km	30 seconds	70 seconds	110 seconds	3
Vampire	III		0.45 km	30 seconds	109 seconds	160 seconds	3
Juruá	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Aigle	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Anshan	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Loyang	VIII		0.45 km	30 seconds	124 seconds	160 seconds	3
Destroyers (except Lüshun)	II - XI		0.45 km	30 seconds	70 seconds	100 seconds	5
Campbeltown	III		0.45 km	30 seconds	109 seconds	160 seconds	3
Gallant	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Destroyers	II		0.45 km	30 seconds	106 seconds	160 seconds	3
Destroyers	III		0.45 km	30 seconds	109 seconds	160 seconds	3
Destroyers	IV		0.45 km	30 seconds	112 seconds	160 seconds	3
Destroyers	V		0.45 km	30 seconds	115 seconds	160 seconds	3
Destroyers	VI		0.45 km	30 seconds	118 seconds	160 seconds	3
Destroyers	VII		0.45 km	30 seconds	121 seconds	160 seconds	3
Destroyers	VIII		0.45 km	30 seconds	124 seconds	160 seconds	3
Destroyers	IX		0.45 km	30 seconds	127 seconds	160 seconds	3
Destroyers	X - XI		0.45 km	30 seconds	130 seconds	160 seconds	3
Destroyers	II		0.45 km	20 seconds	45 seconds	160 seconds	3
Destroyers	III		0.45 km	20 seconds	49 seconds	160 seconds	3
Destroyers	IV		0.45 km	20 seconds	53 seconds	160 seconds	3
Destroyers	V		0.45 km	20 seconds	57 seconds	160 seconds	3
Destroyers	VI		0.45 km	20 seconds	61 seconds	160 seconds	3
Destroyers	VII		0.45 km	20 seconds	65 seconds	160 seconds	3
Z-31	VII		0.45 km	20 seconds	85 seconds	160 seconds	3
Z-39	VII		0.45 km	20 seconds	69 seconds	160 seconds	3
Destroyers	VIII		0.45 km	20 seconds	69 seconds	160 seconds	3
Gustav Julius Maerker	VIII		0.45 km	20 seconds	89 seconds	160 seconds	3
Destroyers	IX		0.45 km	20 seconds	73 seconds	160 seconds	3
Felix Schultz	IX		0.45 km	20 seconds	93 seconds	160 seconds	3
Z-44	IX		0.45 km	20 seconds	77 seconds	160 seconds	3
Destroyers	X		0.45 km	20 seconds	77 seconds	160 seconds	3
Elbing	X		0.45 km	20 seconds	97 seconds	160 seconds	3
Destroyers	II		0.45 km	20 seconds	65 seconds	160 seconds	3
Destroyers	III		0.45 km	20 seconds	69 seconds	160 seconds	3
Destroyers	IV		0.45 km	20 seconds	73 seconds	160 seconds	3
Destroyers	V		0.45 km	20 seconds	77 seconds	160 seconds	3
Destroyers	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Destroyers	VII		0.45 km	20 seconds	85 seconds	160 seconds	3
Destroyers	VIII		0.45 km	20 seconds	89 seconds	160 seconds	3
Ognevoi	VIII		0.45 km	20 seconds	89 seconds	160 seconds	2
HSF Harekaze II	VIII		0.45 km	20 seconds	69 seconds	160 seconds	3
Destroyers	IX		0.45 km	20 seconds	93 seconds	160 seconds	3
Udaloi	IX		0.45 km	20 seconds	93 seconds	160 seconds	2
Neustrashimy	IX		0.45 km	20 seconds	97 seconds	160 seconds	2
Destroyers	X - XI		0.45 km	20 seconds	97 seconds	160 seconds	3
Grozovoi	X		0.45 km	20 seconds	97 seconds	160 seconds	2
Leone	VI		0.45 km	30 seconds	118 seconds	160 seconds	3
Muavenet	V		0.45 km	20 seconds	77 seconds	160 seconds	3
Stord	VI		0.45 km	20 seconds	81 seconds	160 seconds	3
Grom, Błyskawica	VII		0.45 km	20 seconds	85 seconds	160 seconds	3
Stord '43	VII		0.45 km	20 seconds	61 seconds	160 seconds	2
Split	VIII		0.45 km	20 seconds	89 seconds	160 seconds	3
Lambros Katsonis	IX		0.45 km	20 seconds	93 seconds	160 seconds	3
Friesland, Velos, Groningen	IX		0.45 km	30 seconds	127 seconds	160 seconds	3
Gdańsk	X		0.45 km	20 seconds	97 seconds	160 seconds	3

					SHORT-BURST SMOKE GENERATOR
Class or Ship	Tier	Nation(s)	Radius	Emission Time	Dispersion Time	Cooldown	Charges
Dido	VI		0.60 km	15 seconds	35 seconds	80 seconds	5
Dmitry Pozharsky	VIII		0.60 km	15 seconds	40 seconds	70 seconds	4
Belfast '43, Nottingham, Defence	VIII, X		0.60 km	15 seconds	40 seconds	70 seconds	5
Kitakami	X		0.45 km	15 seconds	40 seconds	80 seconds	6
Destroyers	II - X		0.60 km	10 seconds	40 seconds	70 seconds	6
Z-35, Z-42	VIII, X		0.60 km	10 seconds	40 seconds	70 seconds	6

• Radius - the size of a puff. (Puffs overlap.)
• Emission time - the length of time the generator runs, producing new smoke puffs. (also called 'Action time')
• Dispersion time - the length of time each puff lasts before dissipating.

						CRAWLER SMOKE GENERATOR
Ship	Tier	Nation(s)	Radius	Emission Time	Dispersion Time	Cooldown	Charges
Delhi	V		0.45 km	102 seconds	10 seconds	160 seconds	3
Huanghe	VI		0.45 km	90 seconds	10 seconds	180 seconds	3
Mysore	VI		0.45 km	90 seconds	10 seconds	160 seconds	3
Hobart	VI		0.45 km	102 seconds	10 seconds	160 seconds	3
Perth	VI		0.45 km	90 seconds	10 seconds	180 seconds	3
Uganda	VII		0.45 km	102 seconds	10 seconds	160 seconds	3
Haida	VII		0.45 km	90 seconds	10 seconds	80 seconds	3
Auckland	VIII		0.45 km	102 seconds	10 seconds	130 seconds	3
Encounter	IX		0.45 km	102 seconds	10 seconds	130 seconds	3
Hector	IX		0.45 km	90 seconds	10 seconds	160 seconds	3
Cerberus	X		0.45 km	102 seconds	10 seconds	130 seconds	3
Vampire II	X		0.45 km	90 seconds	10 seconds	120 seconds	3

						EXHAUST SMOKE GENERATOR
Class or Ship	Tier	Nation(s)	Radius	Emission Time	Duration	Cooldown	Charges
Kitakami	X		0.45 km	30 seconds	10 seconds	80 seconds	4
Battleships	VIII - X		0.51 km	45 seconds	10 seconds	180 seconds	3
Giuseppe Verdi	IX		0.9 km	60 seconds	15 seconds	180 seconds	3
Sicilia	X		0.9 km	60 seconds	15 seconds	120 seconds	4
Cruisers	V - VI		0.51 km	25 seconds	10 seconds	180 seconds	2
Cruisers	VII - XI		0.51 km	40 seconds	10 seconds	180 seconds	2
Francesco Ferruccio	VII		0.51 km	22 seconds	10 seconds	180 seconds	2
Michelangelo	IX		0.51 km	40 seconds	10 seconds	150 seconds	2
Gorizia, Napoli (B)	VII, X		0.51 km	40 seconds	10 seconds	140 seconds	2
Destroyers	II - VIII		0.45 km	25 seconds	10 seconds	90 seconds	3
Destroyers	IX - X		0.45 km	40 seconds	10 seconds	80 seconds	6
Paolo Emilio	IX		0.51 km	35 seconds	10 seconds	140 seconds	5

An angry Fletcher in her smoke screen, preparing to engage the enemy.

Why Smoke ?

A smoke screen does one thing: it obscures vision, preventing those outside the smoke from seeing into or past it. The effect applies equally to ships inside a smoke screen: a ship in smoke can target an opponent at range, but someone else must spot it for her. In terms of detection, smoke interrupts line-of-sight (LoS). Any ship may enter or use a smoke screen, even if it was laid by the enemy.

The vision obscuring effect is not absolute; within the assured detection range ships detect each other without regard to LoS. The range is typically 2.0km but can be increased. There are also counters to smoke. See below.

Within a smoke screen, a ship cannot be spotted by aircraft, even if it is firing at them or someone else.^[1] However, a ship in smoke that is spotted by other means is visible to and can be attacked by aircraft.

Fire on a ship concealed by smoke does not increase its visibility.

Smoke has no effect on the spotting of torpedoes. [unconfirmed]

Mechanics

Smoke timer in action.

When activated, a smoke generator produces "puffs" of smoke^[2] at regular intervals for the emission time listed. Puffs are stationary; they do not move. They do overlap. Taken together, the puffs form a smoke cloud or smoke screen. After a certain period, the puff dissipates. Eventually, so does the entire cloud.

Rather than having to watch the clock or guess when a smoke screen is due to dissipate, there is a UI feature^[3] - a Smoke Timer - that can be displayed to the upper left of the aim point on the battle screen.^[2]

All smoke screens have the same concealment effect but can vary widely in other characteristics.

• Emission time - the length of time the generator runs, producing new puffs.
• Duration time - the length of time each puff lasts before dissipating.
• Radius - the size of a puff, about a half kilometer.

Variations

The Fletcher moves out as her smoke screen dissipates.

Most ships with smoke have two (2) base generator charges with a 240 second cooldown, producing puffs of 0.45km radius. Otherwise, the performance of the generators varies by nation. E.g.

• USN smoke is outstanding, with exceptionally long-lasting puffs.^[4]

• Royal Navy cruisers produce large puffs with nearly as long duration as the USN. They also hide well in smoke while firing. Royal Navy destroyers are quite different, with short emission and duration, but with five (5) base charges and a very short cooldown.

• A few ships can mount a Crawling Smoke Generator  with long emission time and short duration, with the ability to maintain concealment at 1/4 speed for the full emission time.

• Taking this ability even farther, Italian cruisers mount an Exhaust Smoke Generator  that maintains concealment at full speed for the full emission time.

• French destroyers do not mount smoke generators, resulting in a unique play style.

Enhancements

• The premium version of the consumable with an additional charge and shorter cooldown.
• The Superintendent commander skill, for an additional charge.
• The Smoke Screen Expert skill, for a 20% larger puff.
• Reload bonuses from signals (November Foxtrot) and skills (Jack of all Trades) to decrease cooldown time.
• The Smoke Generator Mod 1 special upgrade for +30% emission time in exchange for -5% duration. (This might be especially useful on the moving generators.)
• Minotaur's unique upgrade Enhanced Smoke Generator is a major enhancement.
• Yueyang's unique upgrade Enhanced Armaments actually decreases the effectiveness of her smoke.

Firing in Smoke

A ship sailing peaceably along has a certain detection radius. However, the moment she lights off her main battery, she becomes visible from considerably farther away. This is due to 'gun bloom' — the flame and smoke from her rifles. With clear visibility, the ship's detection range becomes the same as her main gun range.

There is a similar effect when firing in smoke. A ship sitting quietly in smoke is invisible outside 2.0km (barring the use of radar or hydro). When she fires her main batteries, her detection range increases, although not as much as firing in the open.

The amount the ship's detection range increases tends to track the main gun caliber, as does the type of ship. Roughly, the smoke firing detection ranges of DDs varies between 20-25% of the clear firing range, cruisers 35-55%, and BBs 65-100%. Battleships gain little from firing in smoke.

Pan Asian cruisers have a considerable advantage: they have almost no detection range increase when firing in smoke.

Upon firing the main guns, the ship's detection range increases. If no enemy ship detects it, the range immediately drops back to the non-firing detection range. If an enemy ship does detect it, the ship remains spotted for at least 20 seconds before the range reverts to the non-firing detection range. Of course, firing again resets the 20 second timer.

Note well that while gun bloom may not cause the ship to become detected, the muzzle flashes and tracers themselves are visible to the enemy from a considerable distance, and may be quite sufficient for accurate counter-fire.

For more information on how the spotting and detection system works in World of Warships, please see the Detection article.

Counters to Smoke

The concealment effect of smoke can be countered by alternate methods of detection: radar, sonar, radio direction finding. And a ship concealed by smoke still can be attacked.

Surveillance Radar

Radar is not hindered by obstructions to LoS; smoke and terrain are no obstacle out to as far as 12 km. See the Surveillance Radar  consumable for details.

Usually, radar is used to spot and target ships hiding in smoke. However, radar works both for a ship looking into smoke, and for a ship looking out from smoke. A radar ship illuminating targets from within a smoke screen can fire on her enemies without herself being seen (assuming that they remain outside her detection radius).

Hydroacoustic Search

The effect of the Hydroacoustic Search  consumable is similar to radar, though with a longer duration and a shorter range. In effect, it increases the assured detection range to 3, 4, 5, or even 6 km.

'Hydro', of course, also has its usual defensive ability to detect the torpedoes coming from that suspicious cloud over there.

Radio Direction Finding

The RDF commander skill displays an approximate bearing to the closest enemy. Especially at a relatively close range, RDF can provide enough information for effective torpedo or gun counter-fire.

Torpedoes

Torpedoes are not a counter to concealment; they are a counter to concealed ships. Firing a spread of torpedoes into a smoke screen may have serious consequences for ships inside or behind, often turned broadside to unmask all turrets and thus offering big, fat targets. Even if the fish don't hit, they may force the lurker out into the open.

The captain launching torpedoes should consider how long the smoke screen will last. Torpedoes are much slower than shells and a smart captain hiding in smoke will be gone by the time the screen dissipates.

Counter-fire

The general whereabouts of a ship firing its main guns (not secondary or AA guns) in smoke can be observed by its muzzle flashes, even if the ship itself cannot be seen. This can be enough to place shells very near or on the concealed ship. It's a skill worth practicing. Fast-firing ships may simply saturate the area with shells and watch for explosions as they make contact.

The captain hiding in smoke must be aware of the possibility of counter-fire. He can adjust his movement and positioning, or even hold his fire, to make counter fire much less effective.

Maneuver

Ships are longer than they are wide. A common albeit questionable tactic is to steer nose-in, order flank speed, and charge the smoke. Such a ship is positioned to dodge torpedoes and absorb gunfire. Relying on her forward guns, not every ship has the firepower to quickly kill a revealed enemy, so this tactic is discouraged for destroyers. A battleship that pulls it off can simply run over a previously-hidden destroyer. Cruisers don't like to be rammed, either.

Tactics

There are several ways to deploy smoke, and different ways to use deployed smoke.

• A ship setting up a firing position may circle to make a large cloud in which she can take different positions to baffle counter-fire.

• A ship masking off a large area or corridor for other ships may lay smoke at high speed to create a long smoke screen that hides friends at they move across open ocean.

• A ship may place her smoke in a gap between islands, then move on to other tasks.

Snatching a Cap

A common tactic of destroyers in the opening stages of a battle is to move into a capture point (Cap) and "pop smoke". The enemy already will know that there is a ship in the Cap, though not where it is. This leaves the enemy with a tactical problem: surrender the point, send a ship (usually the lead destroyer) into the Cap to contest it, or find the smoked destroyer and kill it. At this point, the situation usually turns on the positioning of support ships.

Generally, this is considered a questionable use of smoke. The Capping destroyer has blinded herself to threats, and probably blinded supporting ships behind her. In addition, the smoke cloud is a dead giveaway of where the destroyer is located. Better to hold onto the smoke charge until it's truly needed.

The Getaway

A ship may advance to contact, hoping to spot the enemy fleet, then suddenly find herself the subject of way too much attention. She will pop smoke, come hard about, and run for her life. While the smoke may not conceal her directly, it will be between her and most of her enemies, hoping to baffle their gunners long enough to break contact.

With luck, the ships firing at her will themselves be spotted and have new things to worry about.

Bound and overwatch

This is a combination tactic used around a capture point (Cap). A destroyer and cruiser team up to exert pressure into the Cap, or perhaps win it. The destroyer pops smoke at the edge of or even within the Cap, the cruiser enters the smoke and takes up a firing position. The destroyer then leaves her smoke to spot for the cruiser and perhaps knife-fight while the cruiser provides cover.

The success of this tactic is highly dependent on the local terrain.

Obscuring fleet movement

A smoke screen can obscure a wide area from an enemy at a distance. Particularly at choke points between land masses, the view of an entire section of the map can be hidden so friendly ships maneuver without being seen.

Saving a teammate

A valuable use of smoke is defensive. If a friendly battleship is under heavy fire, interjecting with a smoke screen may be just the thing to save it and keep those guns firing. Likewise a cruiser that suddenly discovers an uncharted island. Such altruism can save a win and might even be worth a karma point.

The Invisible Ship

A ship pulls into a favorable location, perhaps overlooking an ongoing fight, deploys smoke, and opens fire. This tactic is particularly suitable for ships with fast-firing guns and long-lasting smoke, such as USN destroyers. The difficulty is that the "invisible ship" rarely remain invisible for long. It is recommended that a ship practicing this tactic plan an escape route, such as behind a nearby island.

Pretending to be an island

If the range is long enough, a ship may place a smoke cloud, then sit in the open behind it to lob shells at the enemy, essentially treating the cloud as an island. The virtue of this tactic is that the ship can continue to spot for herself, while remaining obscured from enemy binoculars. And at need she can duck into her cloud for more stealth.

A more common tactic is to set a smoke screen for a more powerful ship to sit behind and shoot while the original setter spots or continues to other tasks.

Notes

1. ↑ How It Works 9: Spotting Part III.
2. ↑ ^{2.0 2.1} Smoke puffs are more easily visualized by enabling 'Show Smoke Boundaries' option to show the boundaries of smoke clouds laid by both friends and enemies once you are close to the border of the cloud. This and the 'Show Smoke Timer' option appear on the Settings.Controls panel, lower center. Both are recommended.
3. ↑ The Smoke Timer was introduced in Update 0.6.3.
4. ↑ This is historically accurate. In WWII, the composition of USN smoke was a closely guarded secret.