OKLAHOMA CITY - The U.S. Army Corps of Engineers plans to increase safety patrols on Oklahoma lakes following a string of recreational drownings.

Corps spokesman Matthew Nolen says officials plan to encourage the use of life jackets following the drowning deaths of 11 people in Oklahoma lakes since May.

Nolen says most drowning victims are not swimmers and fall into the water unexpectedly from a boat or dock. Officials say consistent life jacket use could reduce drownings by 90 percent.

Two drownings have been recorded at Lake Eufaula in northeastern Oklahoma during the past week, including a man who drowned Tuesday evening and a four-year-old boy who drowned Thursday morning.

The Oklahoma Highway Patrol says an 18-year-old man drowned on Friday in Frederick Lake in southwestern Oklahoma.

OHP's Marine Enforcement Division will hold boater education courses at Bass Pro Shops August 11 and 25 and September 8. The course is required for some younger boaters, and most insurance companies offer discounts for boat owners who have successfully completed the course, OHP states.