I remember once at Bremgarten seeing some guys with a Plank of wood (resembling a shortened door I guess) that they attached a bungy cord to. The other end was attached to the Bridge.

You hold the board vertical in the water and get pulled downstream, stretching the cord. When you are ready (stretched the cord enough), level the borad off and get sligshot back upstream.

I had a go and is was great fun.

Maybe this could be done on the Limmat, but you might get hauled out by the river/lake police.

Yes Wakeboarding is not cheap here, but compared to the costs (time & money) of heading somewhere for the day, might not be so bad in the end.

We used to head down to Ticino for the odd weekend to a place for Wakeboarding. Can't remember the detials but I could probably dig it out again if anyone was interested.