Wet Feet

A double jump being performed in the air with the help of wet feet.

Wet feet, sometimes referred to as airplane, is a movement technique that sets Jak to a grounded state while in mid air. This grounded state gives Jak the ability to perform a limited amount of other movement techniques as if he were standing on a normal ground surface. These movement techniques include combinations of jumping, punching, spin kicking, and zooming.

The technique is called wet feet because the setup requires Jak to enter a body of water for a moment. It is also referred to as airplane because it gives Jak a horizontal ground plane in the air that allows for more movement inputs.

Technical

The technique is performed by first entering one body of water, and then, without moving below the original body of water vertically, moving above another body of liquid (including dark eco or lava). Upon falling to the vertical coordinate of the first body of water, a standing state will be obtained for a short time, allowing the execution of other actions.

It's been observed that several height and Y-coordinate fields within Jak's water-control field are not properly reset while in Wet Feet state, however it is believed that there are other conditions required to trigger Wet Feet that we haven't yet isolated.

For instance, you can set up the Sandover Wet Feet scenario in OpenGOAL by manually setting the water-control fields:

(define wet-feet-height (meters 10.95))
(set! (-> *target* water height-offset 0) 0.0)
(set! (-> *target* water height-offset 1) 0.0)
(set! (-> *target* water height-offset 2) 0.0)
(set! (-> *target* water height-offset 3) 0.0)
(set! (-> *target* water enter-water-pos y) wet-feet-height)
(set! (-> *target* water base-height)       wet-feet-height)
(set! (-> *target* water surface-height)    wet-feet-height)
(set! (-> *target* water bottom-height)     wet-feet-height)
(set! (-> *target* water height)            wet-feet-height)
(set! (-> *target* water bottom 1 y)        wet-feet-height)
(set! (-> *target* water bottom 0 y)        wet-feet-height)

However the same set up (wet-feet-height adjusted accordingly) does not seem to work in all areas of the game, so we suspect there's more to the story.

Discovery

Bobbykaze sharing his first encounter with wet feet on Discord

There is an instance of wet feet that commonly occurs in Lost Precursor City, but Bobbykaze was the first runner to discover that the technique was directly related to Jak interacting with water. After messing around with the water fountain in Sandover Village, Bobbykaze made his way over to the farmer's hut and encountered a mid air standpoint when roll jumping off a small ledge. He then reported the incident in the community discord server on June 24, 2020. Other speedrunners and glitch hunters soon began investigating the technique and where it could be applied in speedruns.