Bernie is acting super gay and wants you to have some fun with him. Take him out for a boat ride.
Let's Go Boating
After the cutscene, Bernie will ask you to take him toards the beach on Firefly Island, so drive the boat over to the GPS co-ordinates. Pull into the mission objective marker, and after the cutscene some of Dimitri's guys will shoot at you. Chase after them but save your ammo. As usual, whenever you're told to chase someone and kill them, what they really mean is chase after them and when they stop, kill them.
Dry Land Firefight
Stay with them, and try not to flip your boat, then eventually they'll pull over at some docks. Beach the boat and jump out. Kill the guy on the wooden pier, then head up the hill and take out the two guys remaining.
Once they're all dead, head down to see Bernie.
- Like cars in previous GTA games, the boats will flip over very easily. If this happens it's mission failed, so drive carefully and don't crash if you can help it.
- You can get away with driving the boat pretty much straight along the river. Don't worry about following the lead boat through it's tricky turns, just drive straight the whole way.
- Don't waste any ammo on the boat. You can only kill the enemies once they're on land.
- Drive your boat as hard into the beach/cliffs as you like, you don't need to leave it in the water.