Get a plane and fly all the way to either the southeast, southwest, northeast, or northwest of the map where the ocean is found. Keep flying for thirty minutes in that direction, then jump out of the plane. Do not open the parachute and intentionally drown. When you arrive at the hospital, check your map. You will see that there are enormous amounts of new territories in San Fierro, Las Venturas, and some in Las Santos. You can take over these territories, and they only have one wave.