A fishing level of 25 is required to fish in this area.
The fastest way to get to F4 is at the entrance head forward to the water and surf all the way to the bottom left, then go up the stairs on the left and up the first ladder. In this blue rock maze go to the right and down until blue rocks stop you, then go right and take the first path up. Continue forward until you run into more rocks and go right again. Go down, right, follow the maze, up, left, more maze and take the ladder down. Go down and take the stairs on the right and follow right and down the skinny path to water. Surf right and up onto land. Walk up and up the steps heading forward and right along the wall. Then down a bit to the ladder leading down. Walla, F4. Good mining, Mining Guru that sells the Super Pickaxe for 35,000(35k), fossil shards and Milotic fishing. GL