Grand Theft Auto: San Andreas/Amphibious Assault

After the cut-scene, head for the yellow blip near Pier 69. After the cut-scene, you will be in the water. Follow the red markers to get out to sea, then head for the ship. You have to swim underwater to avoid being noticed. When you need to resurface for air, you will not be spotted if you stay still. Once you get to the ship, you can either stealth kill all the guards, or go in with guns blazing. When you get onto the bridge of the ship, head downstairs, take out a few more guards, then step into the red marker and press Triangle to plant the bug. Get back to the deck, and jump into the water. Then swim back to the yellow blip to complete the mission.

Tips

 * If you like, you can destroy all the patrol boats instead of avoiding them.
 * The other way to save yourself some stealthy swimming is to just take out the guards on the patrol boats. You will need to bring a sniper rifle and climb on the last rock outcrop just before heading to the open sea. You should be able to snipe out the guards on the two nearest patrol boats. You could then take control on one of these two boats and use it to snipe out the remaining guards on the other patrol boats. You could then drive it to the ship. If you park your boat properly besides the ship, you could ride it on your way back too!

Rewards

 * Cash: $11,000
 * Respect: +25