It’s true. The eco (or fuel economy) mode on the Sea-Doo 210 Challenger gives better gas relief than Beano. Here’s how: the computer at the heart of the boat’s intelligent throttle control (iTC) feeds information to the engine, regulating not only the amount of power the engine delivers but also how it’s delivered — in a burst, gradually or steadily. This is all at the driver’s discretion and controlled with a little button on the dash. With the button, you toggle through four modes — ski, cruise, docking and eco, which is the one that gripped us during two separate tests. In eco, the computer found the most efficient fuel flow once the boat was on plane. The computer continued to adjust the engine output as it read changes in current, water temperature, air temperature, barometric pressure and load. We didn’t have to do anything.