it depends. i put xm weather in this season because last year i bagged a lot of days because of "thunderstorm" predictions that turned out to be nothing. this year, i didn't miss any days because of a forecast. i was always able to keep an eye on any storm that actually occurred and determine if i had to head for the docks. even though many of the forecasts for my area weren't good, none of the storms i observed even came close. i also used it for sea state and wind info. there is a lot more and i will investigate that next season.
so if something like that interests you, it's worth it. ron