The Mana Gym is run by Maku, The Voice of the Sea. He seems to be very dedicated to the pokemon in the area and spends time as a lifeguard at Sanji Beach. He is also the only local willing to talk about the constant rain and mist.
"Legend has it, that the people of Mizu Town were a fishing community just off the Sanjii beach. They were relatively peaceful, though tribal. They worshiped the bountiful sea for it's riches, believing a Lapras controlled the sea. However, the people eventually began worshiping another deity, one who brought them sunlight and a good harvest. In anger, the Lapras cast a curse over what would become Mizu Town, using it's power to control weather to create a dense mist or the relentless rain."
- Legend of the Lapras' Curse.
There is a beach outside of Mizu Town known as Sanji Beach. Despite all the bad weather that affects Mizu Town, Sanji Beach remains relatively as normal as a beach can be. Many people and Pokemon can be found here, and one can surf from this beach to Finton Island.