Last Updated Aug 12, 2019 7:11 PM EDT

Chicago — High water levels and powerful currents are creating dangerous conditions for swimmers and boaters on America’s Great Lakes. Sixty people have drowned this summer — nearly half of them on Lake Michigan.

Search crews plied the waters of Lake Michigan last week looking for any trace of a swimmer who went into the water and never came out. A search involved the Coast Guard and small boats.

He’d be the 29th person to drown in the lake this year — a more than 50% increase over 2018. Last year at this time there were 19 lake drownings.

Lake Michigan has had nearly as many drownings as all the other Great Lakes combined. This summer, waves have routinely risen above five feet along the lakeshore. A snowy winter and the wettest June in history have boosted the lake to its highest monthly level since 1986.

A powerboat hit a submerged Chicago jetty July 11 and a passenger died.

Then there are the rip currents.

In early July, Rahem Mason, 17, disappeared into the surf at Michigan City, Indiana. Yolanda mason is his mother.

“I want my son. I want my son,” Yolanda, his mother, told CBS News. “I want some answers.”

When CBS News caught up with David Benjamin of the Great Lakes Surf Rescue Project, he was teaching a lifeguarding class.

“A person struggling in the water can submerge in less than one minute,” Benjamin told a class of soon-to-be lifeguards.

Summer weather draws millions to the lakefront, where Benjamin said many people mistakenly think if they can wade, they can swim.

“A rip current opens up and now that waist-high water you’re standing in — all of a sudden your feet are sinking in the sand or the sand’s being pulled out from under your feet and you have water over your head and you go to instant panic,” he explained.

Rip currents — which happen in oceans and lakes — can move as fast as eight feet per second. So it’s no wonder that they account for 80% of all beach rescues.