Fishy Skip allows us to reach the Coast and Lighthouse levels without needing to go through Fishy Clues, thus avoiding the 450 Snack Gate. There are two parts to this skip: Pier 2 Void Warp and Coast 1 Keys (Fish Cringe)

Pier 2 Void Warp

In Pier 2, we are able to do a Void Warp by clipping under the water. This teleports Scooby to the intended entrance of the level which, in this case, is the door leading to Pier 1. Pier 1 is also the level you end up in after traversing through Fishy Clues. From Pier 1, we are able to access Coast 1.

Coast 1 Keys (Fish Cringe)

Since we need the Helmet to obtain the Super Smash, we have to be able to warp back to the Coast levels later. We don’t use the Warp Gate in Fishy 4 because that would force us to pay the 450 Snack Gate that we are trying to skip. The only other Warp Gate we can use is in Coast 3. To reach it, we first need to unlock the door at the end of Coast 1 by clipping into 4 boxes to collect the keys. For the box in the middle of the room, we have to use the Fish Monster to help us clip inside.

Here is a full video tutorial covering both parts of Fishy Skip:

Here is another in-depth tutorial focusing on Coast 1 Keys: