Jet ski in Mazuria can be used at all designated navigable routes beyond the "zones of silence" such as Dobskie lake reserve and Nidzkie lake reserve.
In many places, however, they are speed restrictions and / or waves ban which limits the possibility of free jet skiing. The largest concentration of jet ski enthusiasts in Mazuria are the place Rydzewo near Gizycko.
A good place (where there are no restrictions) for motorboating sports are big lakes: Niegocin, Sniardwy, Dargin and Mamry.
One more thing: towing eg. a wheel, skier, etc. is allowed only in designated areas in Mazuria. Such area is for example on the lake Niegocin in the vicinity of the Wilkasy village.
"River Raid Poland Zegrze - Mikołajki Water Jet"
It could be an event or an organised trip: water-jet.com.pl/en/cruises-trips