Connect the Dots

Get in the chopper and fly to the enemy boats (marked with red triangles on the minimap (a small map usually in the corner of your screen)). Use the helicopter's weapons to destroy them. Be wary of the missile batteries (SAMs), and try to destroy them before they notice you.

Use your chopper to destroy incoming enemy boats and helicopters. If your helicopter is destroyed, hijack another one and use it to destroy the remaining enemies.

Get in the gunboat and drive it to the marked location. There will be red mines everywhere, so move carefully and make good use of the jump and nitrous (boost) to avoid them.

Get in the boat again and reach the next destination. There will be more mines, so be careful.

Use the boat to get to the final destination. Try to stay away from the mines; the boat can only handle one or two of them.

Destroy the first two incoming boats with Rico's weapons. Then a chopper will spawn; hijack it and use it to easily defeat the rest of the incoming enemies. Enemies will spawn from every direction: land (vehicles and snipers), air (more helicopters) and sea (boats and a battleship), so make good use of the helicopter to protect your allies. Once you defeat them all, the mission will be complete.