Authorities are issuing a warning for those looking to go on the Delaware River, stating they must be wearing a life jacket at all times.

The warning comes after 20 people were rescued in Orange County last weekend on the river.

The Delaware River in Orange County is one of the most paddled stretches of river in the world, according to United States Park Ranger Kevin Reish.

He says last weekend the river had 6-to-8 foot waves, causing dangerous conditions for boaters.

Three rangers- Dean Hill, Richard Franke and Reish - saved 20 boaters Saturday in a mere matter of hours. They were the only professional rescuers on the water.

“It was a life-or-death situation,” says Hill.

Reish, a national water safety expert, says all those saved Saturday were luckily wearing lifejackets.

“Many of them might have not lived if they weren't,” he says.

Rangers say boaters should check river conditions before planning a trip to the river.