After Trevor decides to take the plans using a chopper and a submarine, the player needs to steal a yellow Submersible, which is hanging off the freighter located in the Port of Los Santos. To free the submarine, Trevor can sneak onto the ship and release the cables holding the submarine using an on-ship control panel. There is one guard that Trevor must either avoid or kill. Alternatively, Trevor can use a sniper rifle to take out the cables holding the submarine, which lets the submarine fall into the water. Either way, Trevor must then board the submarine and pilot it to a different part of the port. There, Floyd pulls the submarine from the water using a crane and places the submarine on a tractor trailer. Trevor and Floyd tie down the submarine, then together drive it to a port warehouse for safekeeping.
Retrieve the sub.
Go to the extraction point.
Drop the sub off at the warehouse.
Get out of the truck.
Gold Medal Objectives
Time - Complete within 08:30.
No Boarding - Steal the Submersible without boarding the boat.
To achieve the Gold Medal for this mission, the player must use the sniper rifle method, shooting the cables holding the Submersible, diving into the water and then swimming around the boat to the Submersible.