The Cayo Perico Heist is one of the biggest heists in the history of GTA Online.
In order to pull off this daring heist, players, along with Pavel, must undertake a series of elaborate prep missions.
One of the prep missions requires the player to steal a sonar jammer from the Merryweather Test Site. Those who have played through GTA 5's Story Mode are well aware of Merryweather.
Players can take on this mission solo or with a crew of 4. However, a Motorcycle Club in GTA Online can build a crew of up to 8.
The mission involves stealing a sonar jammer from a submarine at the Merryweather Test Site and then delivering it to the Kosatka.
The sonar jammer in GTA Online's Cayo Perico Heist Prep
The sonar jammer is of utmost importance to the Cayo Perico Heist in GTA Online. El Rubio's island has an extensive sonar network, and the Kosatka will need a jammer to approach the island.
Pavel will hand the player the approximate location of a submarine test that involves the jammer. However, the player must find the site and steal the jammer. Since the Kosatka is a driveable submarine, players can use it to travel to the last known location of the Merryweather Submarine.
From there, players can either use a dinghy to travel to the test site. However, a Toreador would be very useful here due to its ability to double as a submersible. A dead giveaway to the location of the site is the presence of a Buzzard and three boats on the surface.
Players will then have to look for the Merryweather Submarine beneath the ocean surface and make their way inside. After this, they must make their escape and complete the mission.