The Hydrophobic Gap is one of the final series of ramp jumps you can find in the Downhill Jam course in Tony Hawk’s Pro Skater 1+2. Thankfully, it’s in the middle of a bowl that you can freely use to gain plenty of momentum, so completing an Air Walk over the gap should be fairly straightforward. The exact location of that ramp can be a bit annoying to land, though.
You can find the pair of ramps you need to perform the Air Walk on near the course’s end. Make sure to catch them before you reach the end of the course, or you could be sent straight to the starting point again.
The move you want to perform, the Air Walk, is a Grab Trick. You can do it by making a down right move on the directional pad, and pressing the grab trick button while in the air. You want to have plenty of air to make it across the ramps successfully.
The trick to land this one successfully is having enough momentum and gaining enough air. Before you make it to the gap, make sure you have your special bar filled, and it’s going. It gives you a minor speed boost. You also want to have enough air to clear the gap and do the move. If you don’t have enough air, you can perform the Air Walk, but you won’t clear the gap, which is making it across the back ramp from the first one.