Saving Oliver | Main missions Far Cry 3 Guide
Last update: 11 May 2016
You must, absolutely, reach the marked area by car. Once you approach the area in which you are to take the quest, you will only have one minute and forty seconds to reach the marked area to the south-east. Ignore the enemies on the way and go directly towards your destination point. After you reach the village, where Oliver is being held captive, get out of your car and take a walk through the passageway shown in the screenshot.
After you watch to the cutscene, on the scarp, you will be automatically equipped with sniper rifle. First, you need to snipe down the guard that is escorting Oliver to the chopper (it is not necessary that you are accurate).
Then, you need to cover him by killing the enemies that are after him. You can make use of explosive barrels, to get rid of multiple enemies with a single shot.
When Oliver reaches the boat, jump into water and mount the turret. Shoot at other boats and cars that chase you along the road. At some point, you will also have to destroy the chopper. When there are no more enemy vehicles left, the mission completes.