Echolocator

The Echolocator is a special weapon in Splatoon. When activated, enemies' positions are revealed to the player and their teammates for nine seconds, unless the player is employing the ability Special Duration Up, which increases Echolocator's tracking time respectively (+1.5 seconds per Special Duration Up main, and approximately +.45 seconds per sub).

Splatoon
It is similar to the Point Sensor, but it allows the user and their entire team to see all enemies rather than just those in range of the Point Sensor. It also completely refills the player's ink supply upon use, like all specials.

Use

 * This special is especially useful for tracking players who use Ninja Squid, as their locations will be revealed regardless of this ability.
 * Since the Echolocator refills the player's ink supply upon use, but does not affect the actual weapon, it can be effectively used as a free, instant refill when ink is running low.
 * This special is very useful for Chargers, as they know exactly where all the players are, in or out of ink, allowing a much easier shot.
 * When the player uses this special, four arrows spread and fly to the enemies from the player. Enemy players can see this effect, which means that the location of the Inkling activating Echolocator is very briefly revealed to opponents.
 * The ability Cold Blooded will reduce the amount of time the player's location is revealed by the Echolocator by 50% (as of Version 2.7.0).
 * Little else can be done to counter the effects of this special, so taking up a defensive playstyle for the duration of the special can help players stay alive.

Quotes
"Echolocator instantly reveals the locations of all opponents on the stage for approximately twelve seconds. And it doesn’t just work for you. Your teammates can see the locations of the enemy too. Opponents are shown on the screen as circling squid icons. The lines extending from your character’s feet show the direction in which each opponent is located—so even if an enemy is behind you, you get an indicator. With a quick glimpse, you can see exactly where each enemy is positioned. Use Echolocator in conjunction with a teammate’s Killer Wail or Inkstrike. By knowing the locations of each enemy, aiming the Killer Wail and Inkstrike specials is much easier, resulting in more splatted opponents."

- Splatoon Prima Guide

Trivia

 * The name "Echolocator" is based on the term echolocation, a means of navigation used by many marine animals, such as dolphins, porpoises, and toothed whales.
 * There are no brushes or blasters that have the Echolocator as their special weapon.