I am lucky enough to live close to a cable park in Milton Keynes which was first opened about 15 yrs ago as a cable waterski but wakeboarding has since taken over in popularity. It is a cross between skateboarding, snowboarding and surfing, with a bit of open water swimming thrown in when you fall off. Season ticket is £220 for Apr-Oct open between 4 to 7 days per week, so cost is almost negligible once you have the kit which can be had for around £150 used up to maybe £600 new but lasts pretty well unless you are really hammering it. You need to be fairly gym-fit to do it, as starting and being dragged along and round corners at 29mph is tough, particularly on beginners. The hard part though is having the bottle to do the ramps, rail, kickers and aerial stuff. A botched landing doesn’t usually hurt as much as hitting snow, wood, dirt or tarmac, but you can still hit a hard box or catch an edge and apply a lot of leverage to joints (had a bit of a detached-retina scare last year too, but all ok now). I have found it addictive though, and great fun to compete with a growing kid. Motivates me to do some weights and abs in the winter ready for the next season plus it has made me a bit more willing to try more tricks when snowboarding, skiing, mtb-ing/bmx-ing and mx-ing.
A growing sport with a lot of parks appearing in UK, Europe and further afield, and it was going to be an Olympic demo sport soon.