While against the left wall, crouch jump and spark diagonally at the top of the jump. The easiest way to crouch jump without using the flash suit is to hold shot.

Requires:

"h_canUnderwaterCrouchJump"
{
  "useFlashSuit": {}
}
{
  "or": [
    {
      "shinespark": {
        "frames": 13,
        "excessFrames": 3
      }
    },
    {
      "and": [
        "canSunkenTileWideWallClimb",
        {
          "shinespark": {
            "frames": 13,
            "excessFrames": 9
          }
        }
      ]
    }
  ]
}