Before the Mission
You must have at least 50 points in lung capacity in order to start this mission. If you don't, Carl tells Woozie that he can't swim.
Woozie has another job for you, but it requires the ability to swim well underwater. Woozie says he is afraid of deep water, and further confesses that he's blind... although he has trained his senses to a point where you wouldn't notice his handicap. Carl Johnson says that when he was a little boy swimming down in the Santa Maria Beach, he had a condom stuck to his face.
Get to the docks near Pier 69 in Esplanade North. The boat that you have to plant the bug on is anchored out at sea. You will have to swim to it, however, there are Da Nang Boys patrolling the route with Tropics. Swim to the tanker and get aboard. You must swim through the red markers, and dive underwater in cases where the route is blocked. The main route across the water is guarded by two patrol boats. If they spot you, dive underwater to lose their attention. If you swim on the surface of the water you will be spotted. There are also spotlights searching the area. The large circles on the radar represent the spotlights and their current position.
Swim to the far side of the tanker, and go to the red marker. Climb on board and go upstairs. You must sneak to the back of the tanker to plant the bug, but be quiet so as not to attract the attention of the guards. The red blips on the radar represent the enemy. The arrows point in the direction that the enemy is facing. Examine the enemy's route, and perform a stealth attack to kill them. Either crouch, walk up behind them and attack them with a knife or if you have a Silenced 9mm, you may use that as well, having better range and being silenced at the same time. When you reach the back of the tanker, enter the room, and go downstairs to the red marker. Plant the bug, and get back to the dock. Stop in the red marker to complete the mission.