RedactedNarrative: On 7/9/17 at approx. 1:30pm., V1 was cruising in Elk River at idle speed.  A wake from another vessel caused their small pontoon to swamp and then capsize.  The operator and 3 passengers were pulled from the water by another pontoon boat.  Sgt. and I towed the upside down vessel as near as possible to the western shoreline and tied it to a tree.  Tow Boat U.S. recovered the vessel and returned it to the owner''s residence.  No fatalities or injuries reported on scene.