GRAND RAPIDS, Mich. (WOOD) — For all boaters gearing up for Memorial Day weekend, a warning before hitting the water: make sure you know what type of gas you’re putting in your engine.

Marine authorities, including the U.S. Coast Guard, are urging people to double check before filling up at your local corner gas station and watch out for E15 gasoline.

As most boaters know, boat engines do not handle E15 gas well. E15 is short for fuel that has a 15% mix of ethanol. In boat motors, E15 has shown to cause more engine failure, including a higher rate of engine fires. It can also void the engine’s warranty.

Many boaters like to fill up their boat tanks at their corner station because gas is often cheaper compared to fuel bought at a marina. Normally, that’s not a problem. An ordinance from the U.S. Environmental Protection Agency prohibits the sale of E15 gasoline between June 1 and Sept. 15 because E15 gives off more ground-level ozone. However, with gas prices soaring, President Joe Biden and the EPA announced they would lift that ordinance for this summer, keeping more gasoline on the market and preventing more rises in gas prices.

Lt. Jeremiah Schiessel, of the U.S. Coast Guard, told WWJ-AM that boaters should look for an orange sticker at the gas pump that should also come with a warning about using E15 gasoline in boats.

Jeff Wasil, the engineering manager of emissions testing at BRP/Evinrude, laid out the concerns with Boating Magazine in 2019.

“Since marine engines can run for extended periods of time at wide-open throttle, any increase in exhaust gas temperature will cause issues,” Wasil said.

There are two main concerns. One is motors running on E15 for too long, causing them to overheat. The other: motors sitting idle with E15 in the tank and fuel lines.

“The concern is what happens to the components when the engine is not used for some period of time,” Wasil told Boating Magazine. “This is when the higher ethanol content can start to do its damage to these fuel-system components. Remember, ethanol is a harsh solvent, and more ethanol is an even stronger solvent.”