Use five shots to destroy the seaweed blocks: Buffer the first shot while entering the room. Spin jump for the second shot (landing on the slightly raised platform), firing at an intermediate height in order to destroy two blocks. Fire two shots while standing on the platform. Spin jump for the final shot, and activate the shinespark mid-air.

Entrance condition:

{
  "comeInShinecharged": {}
}

Requires:

{
  "shineChargeFrames": 100
}
"canShinechargeMovementComplex"
{
  "shinespark": {
    "frames": 14
  }
}

Exit condition:

{
  "leaveWithSpark": {
    "position": "bottom"
  }
}

Unlocks doors:

{"types":["ammo"],"requires":["never"]}