However, the men also became trapped in the current and were electrocuted.
All five were rushed to a hospital in Akyazi but could not be saved.
Television footage showed ambulances waiting outside the water park and several people gathered outside the Akyazi State Hospital.
Employees at the water park later cut power at the resort, which is 93 miles east of Istanbul.
Two other people were hurt after touching metal railings near the pool, reports said.
Police officers were conducting an investigation into what caused the electrocutions.
The park is thought to have lacked a residual current breaker that shuts down power to prevent electrical shocks.
Hasan Akcan, Akyazi’s mayor, said the park had received a license in 2012 as a swimming pool and amusement centre. He added that the incident was “saddening.”