"Escape down the rapids" is an objective in the story mission Derailed in Grand Theft Auto V.
Walkthrough[edit]
There are a number of Merryweather Security Dinghy on your tail. As Trevor you need to fend them off. After the first drop you also have a Truck incoming on the right. Deal with it and any remaining boats. All this wraps up with a helicopter coming in after you as well.
As Trevor you have a number of things to shoot down. If you take control of Michaelthen you just have to worry about steering the boat on through the rapids and out to sea.
