This trophy is obtained for for doing the second Heist in the game - the first heist to include all three main characters.

Freighter approach:
You have to steal a mini-submarine in the harbour before you start the mission. Michael will sneak onto the ship to plant some C4, Franklin will clear the way with a sniper-rifle. Switching between the characters is really helpful! Once the ship is blown up, Trevor will take the device with the submarine and bring it to a safer place.

Offshore approach:
You have to steal as well the submarine and a Cargobob helicopter from the Military Base (tough, but fun!). After having found the device in the deep sea, you will carry the whole submarine on your helicopter to a safe place, but will get some trouble with Merryweather on your way.

This trophy will be automatically obtained after completing the twenty-seventh story mission "The Merryweather Heist". This is a mission for all the protagonists and it is the second heist. Here, you steal a super weapon for the millitary (guarded by Merryweather) but unfortunally, you give it to Lester to take it back. The objectives:
Freight option:

• Find a vehicle (for Trevor)
• Go to the Miriam Tuner Overpass (for Trevor)
• Cover Michael while he sets the bombs (for Franklin)
• Plant the four bombs (for Michael)
• Cover Michael so he can escape the ship (for Franklin)
• Detonate the bombs (for Franklin)
• Find the device among the ship weckage (for Michael)
• Go to the device (for Trevor)
• Take the device to the secure area (for Trevor)

Offshore option:

• Go to the Sandy Shores Airfield (for Michael)
• Enter in the Cargobob (for Michael)
• Pick the Submarine (for Michael)
• Go to the location of the tests (for Michael)
• Release the submarine close to the location of the tests (for Michael)
• Use the Trackify application to find the device (for Trevor)
• Pick the device (for Trevor)
• Go to the surface (for Trevor)
• Pick the submarine (for Michael)
• Destroy all the Merryweather reinforcements (for Franklin)
• Go back to the Sandy Shores Airfield (for Michael)