With 3 tiles of run speed it is more lenient to make it past the overhang above the door. Cross Room jump and do not buffer aiming down on entry, because Samus's speed is higher underwater while spinning. Aim down and then turn around just before the overhang. Freeze the fish near the left wall and land on it.

Entrance condition:

{
  "comeInJumping": {
    "speedBooster": "any",
    "minTiles": 3
  }
}

Requires:

"HiJump"
"canCrossRoomJumpIntoWater"
"canMomentumConservingTurnaround"
"canTrickyUseFrozenEnemies"
"canTrickyDodgeEnemies"
{
  "or": [
    "Plasma",
    {
      "and": [
        "Wave",
        "Spazer"
      ]
    }
  ]
}
"h_trickyToCarryFlashSuit"

Dev note: This can be done with SpeedBooster, but there is no point, as Samus can jump directly to the ledge without using the fish.