Original solution made by UtG Mist. I just copied his solution over to this version of the game.
In the Water
When you get to the end of the level. Pull the lever on top of the tower like normal to open up the metal grate. go to the edge of the diving board and jump off, landing on the rim of the water tank. Next, carefully position yourself on one of the grates. Get as close to the edge as you can then make sure you're looking down, then press cn_X to slump over. Your head should fall first and if done properly should be the first thing to hit the water below!If you need to restart
Restart the level from the beginning. Make your way across the water to where the end of the level tank is. Climb on top of it by swinging your arms from side to side grabbing further every time. Once you're up, make your way to the top of the mountain by running up the path where the dam water flows. When you reach the dam you can do one of 2 things.Hardest/Quickest
Either Climb up the stairs and walk the beam from the dam to the tower with the lever.
OrEasier but more time consuming
Do the puzzle and break the dam, then get on the raft and surf to the bottom (potential for another achievement [Surfer]. Then ride the water wheel to the top like normal to get to the top of the tower with the lever.
Now repeat the process at the top!