Line of Sight (LoS) is a stat that will indirectly affect several mechanics, being:

Effective Line of Sight for map routing,
Detection success rate,
Contact trigger rate, for airstrike damage,
Reconnaissance Defense Bonus for LBAS Defense Fighter-Power,
Artillery Spotting trigger rate.

For details on the LoS stat growth please see Stats.

Effective Line of Sight

"Effective Line of Sight" (ELoS, also called "Fleet LoS") is the Line of Sight (LoS) that affect certain maps' routing. Certain branching requirements in sorties are affected by the LoS of the entire fleet, this total LoS following unintuitive behaviors.

As a general rule: equipment LoS is more impactful than ship LoS when determining ELoS.

Formula 33

The Formula 33, sometimes referred to as F33, is the most accurate "Fleet LoS" calculation formula known. It is described as follows^[1]:

LoS Formula 33

[math]\displaystyle{ \text{LoS}_\text{Fleet} = \sum_{\text{All Ships} } \sqrt{LoS_\text{Ship} } + C_{n} \times \sum_{\text{All Equipment} } C_{e} \times ( \text{LoS}_{e} + C_{\star} \times \sqrt{\bigstar} ) - \lceil Q \times Lv_\text{HQ} \rceil + 2M }[/math]

With

[math]\displaystyle{ \text{LoS}_\text{Ship} }[/math] the ship's base LoS .
- Total LoS of Visible Fit Bonuses should be added to this part, unlike equipment improvement bonuses.
[math]\displaystyle{ C_{n} }[/math] the Node factor, it represents the weighting of the formula that is known to vary across different maps and nodes (see below),
[math]\displaystyle{ C_{e} }[/math] the equipment multiplier (see below),
[math]\displaystyle{ LoS_{e} }[/math] the equipment's base LoS , excluding visible fit bonus,
[math]\displaystyle{ C_{\star} }[/math] is the improvement modifier of the equipment (see below),
[math]\displaystyle{ \bigstar }[/math] the equipment's improvement level,
[math]\displaystyle{ Q }[/math] the HQ level modifier, varying depending on the map:
- 0.35 on 5-2 and 6-3.
- 0.4 otherwise.
[math]\displaystyle{ Lv_\text{HQ} }[/math] the HQ level.

[math]\displaystyle{ M }[/math] the number of empty ship slots in the fleet:
- 0 for 6 ships fleet,
- +1 increase per missing ship,
  - This value can increase mid-sortie if a ship is sunk or evacuated.
- -1 for a full Striking Force Fleet (7 ships).

Notes

Equipment LoS weight more than ship LoS.

Equipment LoS Weighting Modifier

The node factor [math]\displaystyle{ C_{n} }[/math] affects the weighting of equipment LoS.

It depends on the map (see the below).

The equipment and improvement multiplier [math]\displaystyle{ C_{e} }[/math] and [math]\displaystyle{ C_{\star} }[/math] will affect the "real" LoS given per equipment.

It depends on the equipment type (see the below).

Because of those factors:

Some equipment are more efficient to provide LoS,
Ship LoS is less relevant, notably in maps with higher node factors.

Equipment Types

Equipment type

[math]\displaystyle{ C_{e} }[/math]

[math]\displaystyle{ C_{\star} }[/math]

Recon

Seaplane Recons

1.2

Bomber

Seaplane Bombers

1.1

Carrier Recons

1

1.2

Torpedo Bombers

0.8

0

Large Flying Boats

0.6

1.2

Small

Small Radars

1.25

Large

Large Radars

1.4

Liaison Aircraft

1

All other equipment types:
	Fighters
	Dive Bombers
	Seaplane Fighters
	Rotorcraft
	Sonars
	Searchlights
	Lookouts
	Aviation Personnel
	Command Facilities
	Submarine Equipment
	Landing Craft
Minisub	Midget Submarines
	Small Caliber Main Guns
	Medium Caliber Main Guns

0

Other equipment types are speculated to be:^[2]

[math]\displaystyle{ C_{e}=0.6 }[/math]
[math]\displaystyle{ C_{\star}=0 }[/math]

Estimated LoS

Data sourced from TsunDB. Values are the lowest and highest reported LoS for routing. Please note that there may be some margin of error due to random routing.

Map	C_n	Origin Node	Lower Threshold	Upper Threshold	Destination Node	Fail Destination	Notes
1-6	3	M	29.7	159.6	J	L	Not meeting composition requirements also routes to L.
2-5	1	G	37.3	87.8	L	K
		I	31.2	59.4	O	H
		J	42.4	91.2	O	H
3-5	4	G	24	337	K	I
3-5	4	H	39.1	321.4	K	J
7-2	??	E	-32.1	136.5	G	F	Appears to be fixed routing based on composition but still plays the LoS routing animation.
7-2	4	I	66.1	294.5	M	L
7-4	??	G	??	??	L	F
	??	E	??	??	K/P	L	Not meeting composition requirements also routes to L.
	4	M	50?	??	O	N	Not meeting composition requirements also routes to N or P.
7-5	4	O	57	??	M	L
7-5	4	P	58	??	T/R	S	Composition determines the T/R route.
4-5	2	K	64.8	146.5	T	L
	2	Q	62	167	N/O	P	Low number of reports.
	??	O	62	167	T	N	Appears to be fixed routing based on composition but still plays the LoS routing animation.
5-2	2	F	64	147	O	H
5-2	2	L	73.8	81	K	N	Low number of reports.
5-4	2	L	57	185	P	N
5-4	2	M	42.3	150.1	P	O
5-5	2	O	63.8	134.5	S	R
5-5	2	P	74.4	167.7	S	Q
6-1	4	G	16.7	218.1	H	I
		H	25.4	201.4	K	E	With AS
		H	23.3	218.1	K	E	Without AS
6-2	3	E	46	179.8	J	I
		H	42.8	42.8	K	G	Low number of reports.
		I	35.7	205.8	K	G
6-3	3	E	19.4	180	G	F	Routing is heavily influenced by composition as well.
6-5	3	G	56.3	196.2	M	K
6-5	??	J	37.2	193	M	L	Appears to be fixed routing based on composition but still plays the LoS routing animation.

Events

In events, LoS cheks are also performed following the same rules, but will additionally vary with difficulties, higher difficulties recruiting higher LoS.

FAQ

Q: Why do I keep getting offrouted?

A: Double check that your fleet LoS according to relevant formula meets the LoS threshold for the map. Viewers such as KanColle Command Center Kai, Poi Viewer, KCANotify, KanColle Viewer and Electronic Observer can calculate your fleet's LoS easily for you.

Q: How do I increase my LoS?

A: Reconnaissance seaplanes are the fastest way to raise LoS. The other easy way is to stack radars. Upgrades to reconnaissance seaplanes are also a good way to increase LoS when slots are limited. It is not recommended to stack carrier-based recons or seaplane bombers because too many can compromise the combat ability of your fleet. Another way is to level your ships. Because LoS increases as you level, marrying your ships means their LoS stat can go even higher.

Q: I had enough LoS, how did I get off routed?

A: Planes that are wiped out no longer contribute to LoS. If you were depending on bombers to hit the LoS threshold, you can fall under the threshold when encountering heavy enemy anti-air.

↑ http://ja.kancolle.wikia.com/wiki/%E3%83%9E%E3%83%83%E3%83%97%E7%B4%A2%E6%95%B5
↑ Default based on Vita datamine

Detection

For more information on this topic, see Detection.

At the start of any Day Battle, "detection" will be attempted by the fleet. Detection is required to take part in the Aerial Combat phase.

Only the Ship's LoS and the LoS from the participating planes is taken into account for the trigger rate:

Contact

For more information on this topic, see Contact.

At the start of any Airstrike phase, "contact" may be triggered, increasing the airstrike power if triggered.

Only the LoS from the participating planes is taken into account for the trigger rate (step 1):

Only the LoS from the participating planes is taken into account for the plane selection (step 2):

LBAS LoS

For more information on this topic, see LBAS Defense Fighter-Power.

Unlike ship mechanics, LBAS do not need/utilize the LoS stat and so this stat is mostly useless.

The only use for LoS is for "Defense Fighter-Power" in air defense mode, where it determines the "Reconnaissance Defense Bonus" ([math]\displaystyle{ \text{Mod}_\text{recon} }[/math]) for Recon Seaplane Recons, Large Flying Boats, Carrier Recons, and LB Land-based Recons:

Reconnaissance Defense Bonus
LoS	ReconSeaplane Large Flying Boat	Carrier-based	LBLand-Based
≥9	1.16	1.3	1.24
8	1.13	-	1.18
≤7	1.1	1.2	-

The LoS on all other aircraft or in other LBAS modes is not counted.

Artillery Spotting

For more information on this topic, see Artillery Spotting.

Artillery Spotting attacks require the use of recons/bombers.