Mercury Aqua Storm
Sailor Mercury crosses her arms while holding her Star Tambourine. She then thrusts her tambourine down while the opposite arm sticks upwards. She then switches arms and points the Star Tambourine towards the sky while making her finger pose near her face with the other hand.
Sailor Mercury then spins around a points the tambourine at her target as a powerful burst of water and blue energy blast fires out of it.