Barges don't have brakes.
And local pleasure boaters on the Mississippi River are being asked to remember this is no routine summer.
The new-bridge construction zone just upstream of the Interstate 74 bridge is a potentially dangerous place.
The U.S. Coast Guard and Iowa Department of Transportation are asking recreation-boat captains to be hyper-vigilant in the busy river. And a local pro, Celebration Belle owner and Captain Scott Schadler, said it is essential for other pilots to pay attention.
"I saw a big boat coming through wide open (full throttle), and I thought: Oh, no. Please don't do that," Schadler said. "There are guys in lift baskets, 60 feet in the air, and they're hanging from cranes that are sitting on barges.
"Any wake could really be a problem, and I'm so worried about them getting tipped into the river."
Others are worried, too.
"The DNR (Department of Natural Resources) and Coast Guard have been great partners, assisting with several efforts, balancing bridge construction activity with recreational and commercial river use," said Danielle Alvarez, I-74 project manager for the Iowa DOT.
While boaters should be slowing down to a crawl when in and near the work zone, Alvarez said, they also need to be exceedingly cautious of other boats. Tow-boat operators, for instance, are constantly crossing the channel between the work areas on either side of the river, delivering workers and supplies.
"Unfortunately, we have had occasions where recreational boaters get too close for comfort to our tugs, which are servicing all construction activities within the project site," Alvarez wrote in an email. "We are often loaded with equipment, and visibility of small vessels can be challenging, not to mention the limited maneuverability of a loaded tow."
Schadler said he understands boaters' desire to get a good look at the bridge build, which he also finds fascinating. But boaters must be aware of the dangers.
"They want to get close to the barges, but those guys in the tugs can't see them, and I don't think some of the boaters know that," he said. "My advice is: Be aware of your surroundings, mostly. If you go real slow, nothing bad will happen.
"It's when you're going fast, and you can't slow down, or you're too close, or throwing a wake — that's when you have a problem."
The half-dozen licensed riverboat captains who operate the Channel Cat water taxis get much of their training from Schadler and other experienced captains with the Celebration Belle. They know exactly how to stay safe when passing through the center of the construction zone.
"We're in constant contact (with other boats in the construction zone)," Schadler said. "They're coming and going from the gap (between bridge piers) the same way we are. One problem is: The working boats can't always see the pleasure vessels as they come out from behind the piers."
In some cases, he said, tow-boat captains use their onboard radios to communicate with the smaller boats, especially those running too fast or too close.
The tug operators also have business to communicate to Schadler, including details about the bridge construction, which crews on the Channel Cats and Celebration Belle can pass along to their passengers. The bridge work, after all, is of considerable interest to all who pass by.
"A tug captain told us it takes 95 cement trucks to fill one bridge pier, and we like to pass those details along," he said.
Some of the barge companies have tried to recruit Schadler, he said, but he's too busy in the summer, running his river cruises and keeping the Channel Cats supplied with licensed captains. In the winter, he said, he'll reconsider. Being a part of the historic build has its appeal, he said.
For now, Schadler hopes to see more pleasure boaters become aware of the dangers in the construction zone. Various agencies have posted information at area marinas, he said, but the information hasn't been posted at a couple of boat-launch sites, so those who trailer their vessels may not be getting word.
But Alvarez said the DOT is working with local parks departments to make sure the River Traffic Advisory posters are placed at all launch sites.
Spreading the word, Schadler said, should add another layer of safety.
"Ninety-eight percent of these pleasure boaters are doing a very nice job of keeping everybody safe," he said. "The Coast Guard puts out a regular 'Notice to Mariners,' and it's a good idea to have a look at it before going out, especially when there's construction in your pool.
"It's really not much different out there than traveling through a construction zone on the interstate in that you need to slow down and be aware of what's around you."