Charges of negligent operation of a personal watercraft and operating a personal watercraft between sunset and sunrise were dropped.
In another case, Myers pleaded guilty in May 2007 to operating a vessel in a prohibited area and negligent operation of a personal watercraft, records show.
Thomas A. Browning, 24, of Hagerstown, who was riding with Myers in July, pleaded guilty last week to three counts: operating a vessel in a prohibited area, operating a personal watercraft between sunset and sunrise, and negligent operation of a personal watercraft.
Online court records did not give any indication of a sentence.
Records show that Browning pleaded guilty in 2003 to operating a personal watercraft at greater than 6 knots within 100 feet of a vessel.
Myers said in a phone interview Wednesday that his probation includes repeating a Maryland Department of Natural Resources boater safety course.
"It's better than being in jail," he said, adding that he will be more careful in the future.
Sgt. Ken Turner of the Maryland Natural Resources Police Department previously said that on July 14 the two friends rode past a set of warning buoys, then past a second set of buoys marking a restricted area about 200 yards from the dam.
Myers, the son of state Del. LeRoy E. Myers Jr., said at the time that he got too close to the dam and jumped off as the watercraft started to fall. He was treated at Washington County Hospital and released.
Staff writer Heather Keels contributed to this story.