You could listen to the VHF radio weather reports all day long and still come away with far less information than you’d get by glancing at a graphic weather presentation—in color—on the display screen of a chartplotter.

Marine electronics companies have joined forces with the two nationally known satellite radio providers, Sirius and XM, to supply this kind of weather information for moderate monthly fees. Here, we take a hard look at who provides the best weather service at the best overall price. …