This mission can only be attempted between 20:00 and 6:00, and Carl also needs to have a Lung Capacity of at least 5%.
Carl meets Wu Zi Mu at his apartment in Chinatown. Woozie explains that he plans to plant a bug on a Da Nang Boys-owned ship in San Fierro Bay. Woozie asks Carl to do this, but Carl is reluctant to do so because of an experience he had (getting a condom stuck to his face) whilst swimming as a child. Woozie later admits to Carl that he cannot do it because he is blind. Carl, sympathizing with Woozie, has a change of heart and agrees to the task.
However, if the player's lung capacity is insufficient before starting the mission, a special cutscene will be triggered. While playing on the CJD 500, Woozie asks Carl if he can swim well, to which Carl replies negatively. The game would then tell the player to improve their lung capacity by diving underwater for the mission to be continued.
Carl makes his way to Esplanade North, near Pier 69. Once there, he dives to the water. He first navigates through a rock formation. Afterward, he sees and avoids the Da Nang Boys patrolling the ship and the sea in Tropics. He also avoids the search lights planted on the tanker. As he arrives at the freighter, he quietly makes his way to the back of the ship, either by avoiding the guards' attention or by killing them. He eventually arrives at the back of the ship, and plants the bug. After planting the bug, Carl leaves the ship quietly and swims back to the dock on Esplanade North.
In order to complete the mission the player must:
Get to the docks
Swim to the tanker and get aboard
Sneak to the back of the tanker and plant the bug, be as quiet as possible to avoid the attention of the guards on onboard
You have planted the bug! Get off the tanker and back to the docks
Should CJ's health be low upon reaching the end of the swimming obstacle course (perhaps from nearly drowning), it is possible to swim back to shore, climb out, and eat at the nearby Well Stacked Pizza Co.. This triggers a glitch- while talking to the clerk at the Well Stacked, the box directing the player how to choose a meal doesn't display, though it's still possible to make a choice.
A rare glitch on the Android version results in the guards on the patrol ships disappearing, though they will still be present on the freighter.
If Carl jumps from one of the patrol boats to the stairs leading to the tanker's deck without falling into the ocean, the cutscene showing the guards will not be triggered and the guards will not spawn, though Carl will be unable to plant the bug on the ship. This can be fixed by alighting and re-boarding the ship.
The reward for completing this mission is $11,000 and an increase in respect. The mission The Da Nang Thang is also unlocked.
Once Carl dives into the sea, he is free of police attention for the remainder of the mission.
The cutscene audio file for the alternate cutscene has an unused line of Carl saying "Shit... damn!" because the cutscene cuts off as soon as Woozie laughs.