Line of Sight

Currently, there are only two known purposes for Line of Sight (LoS):

• A higher total LoS increases trigger chance of artillery spotting for a ship's double/cut-in attack in sorties (daytime).
• Effective LoS, which allows the fleet to reach a specific node (usually a pre-boss or boss node) instead of being diverted to a dead end. Effective LoS is employed in special maps, such as event maps and extra operations maps (2-5, 3-5).

Effective Line of Sight

• Effective LoS = Recon LoS×2 ＋ Radar LoS ＋ √(Fleet total LoS - Recon LoS - Radar LoS). This is the formula used since Spring 2014 event; in 2-5, 3-5 boss node, and any node with the seaplane-searching animation.
• Due to the formula, recon planes will contribute more to effective LoS than radars. For the purposes of fulfilling effective LoS, avoid using radar that does not give at least +10 LoS.
• You can make an exception to the above if your ships require other equipment for more damage, in which case you can make a DD/Yuubari a radar 'mule' to contribute to LoS by stacking radars.
• ONLY Recon planes' (yellow & seaplanes, which are light green planes WITHOUT A LOGO, see this) LOS values are doubled. LOS from attack planes (red & blue) are not doubled, but in fact square rooted. Do not double your attack planes' LOS value when making LOS calculation.
• You know you fulfilled the LoS requirement if you see a short animation with a seaplane flying to the node and back to your ship icon, plus the flagship's image appearing on-screen. Otherwise, you will be diverted off-course to a dead end without the animation playing.

5:06-5:11 of this video here shows what the animation looks like: http://www.youtube.com/watch?v=J-x1tNuCeSE

• You can have a high total LoS and still FAIL the effective LoS requirement. Do not use the total LoS as a guide.

• If you have trouble reaching LoS requirements, take a look at the sortie page (for 2-5, 3-5) or other players' reports (for event maps) and adjust your equipment accordingly

(Events) Variations in effective LoS between players

During the Summer 2014 event, there were many player reports where players of similar HQ levels have differing effective LoS requirements, leading to confusion among many players. This hints to a possibility that effective LoS scales to level. Do not be surprised if you level up or reach the next HQ bracket (e.g. HQ lvl 60-99, 100+) and fail to reach boss node when you did reach the node the previous sortie.