After at least five drownings in the Delaware River this summer, one police chief is renewing calls for a color-coded warning system along the river.

So why are some people fighting the plan?

On a sunny late-summer day, the Delaware River looks calm. But looks can be deceiving.

"People don't really know what they're getting themselves into," said Brian Shea with Paddle Creek Frenchtown, a kayak rental business.

Shea said there's danger beneath the smooth surface.

"It's the stuff you can't see, like partially submerged rocks and logs that will pin you," he said.

Just downriver, crews are still searching for a rafter who launched from Bucks Co. this weekend. It comes after four other drownings this summer.

"It's really not a good idea to be in the river at this level," said Chuck Arkell, Paddle Creek's owner.

But too many out-of-town visitors don't know that, so Arkell and Frenchtown, N.J., Police Chief Al Kurylka are teaming up to push for a new early warning system.

"A flag system would be nice, similar to what they have at the beach," said Arkell.

The idea is to place warning flags at popular launch points, like Frenchtown and Riegelsville. Color-coded flags would correspond to river speeds and levels registered at USGS sites Riegelsville and Trenton, N.J.

The idea has been discussed for years, but with so many drownings this summer, it's now getting a second look.

"They have the same thing along the oceans with warning people to go in the ocean or not, with riptides, so I think it's alright down here," said Pete Kwiatek of Milford, N.J.

"I think that definitely a lot of parents will take that into consideration with young children," added Addison Rolleri of Doylestown. "I think a lot of teenagers might ignore it."

Although it's a relatively cheap idea, Arkell said some people are fighting the idea.

"I think there's probably a negative perception that we want to restrict people's access to the river," he said. "They don't want more government regulation, and I completely agree with them, but I don't know that it would be a regulation so much as an early warning system."

Supporters have met with various state and local governments to pitch the idea, but Arkell said it's difficult to get so many agencies -- in two different states -- to come together.

Meantime, before you go out of the river, you can check the current speed and levels yourself .

Arkell said a discharge level above 17,000 cubic feet per second is dangerous.

You can also sign up for automatic email alerts when river readings reach a certain level.