WOODSTOCK – The Sheriff's Office has investigated three boating crashes on the Fox River in less than one week – including two this past weekend.

Two juveniles suffered minor injuries Saturday after they were thrown from a tube in which they were riding. The incident happened at 2:05 p.m. on the river near the Fox River Grove picnic grounds.

A Kawasaki GTX15F, driven by Scott R. Mattison, was pulling the two juveniles on the tube behind the watercraft when the tube struck the mirror of a Polaris Wave Runner. The wave runner was operated by Daniel Karalus, 52, of Oakwood Hills. He was uninjured.

Both juveniles were thrown from the tube and suffered minor injuries that did not need further medical treatment.

Mattison, 37, of Crystal Lake, was cited with careless operation and overloading.

A 17-year-old Crystal Lake boy was driving a 33-foot Baja Outlaw on Sunday when it struck a Kawasaki 755 Jet Ski near Haegers Bend in Algonquin. The incident happened at 4:45 p.m.

The boat and the jet ski made contact, causing minor damage to both.

The driver of the jet ski, James Hochber, 48, of Arlington Heights, and two occupants of the jet ski were transported to Advocate Good Shepherd Hospital in Barrington for minor injuries.

Alcohol or drugs is not believed to play a factor in any of these crashes.

The juvenile was reported to be driving the boat under parental supervision, the Sheriff's Office said in a news release.

The Sheriff's Office is warning boaters to be careful on the crowded river.

"With the warmer weather there has been an increase of watercraft on the water," Undersheriff Andy Zinke said in a news release. "Operators are encouraged to use extra caution and be watchful of others while operating on the narrow, shallow river."

The crashes remain under investigation. Authorities are encouraging anyone who witnessed the crashes to call the McHenry County Sheriff's Office Marine Unit at 815-338-2144.