The bizarre scene unfolded on the picturesque beach in FIFA World Cup host city of Sochi in western Russia.
According to local reports, the water was not contaminated but was black in colour due to dark soil it was carrying.
Soil and dirt reportedly seeped into the city’s drainpipes during an accident earlier that day.
Samples of the black water were taken and it was found to carry no pathogens.
Authorities added that drinking water had not been affected.