Many years ago I lived in Peterborough, Ontario, and always wanted to arrange some sort of rafting trip down Jackson Creek, which disappears underground through downtown before it empties into the Otonabee River. I thought this could be made into some sort of environmental educational event that i could convince 3 pubs along the creek to sponsor.

So last night i dreamt i did it, except the creek was wide, more like the Otanabee itself, but shallower, and a younger myself & a handful of others were swimming, not rafting. We came up at one point through a sewer grate in the basement of a shopping mall. But near the beginning, we were harassed by a bunch of jerks on jet skis - it was the members of Van Halen, and they were blaring out the song "Jump" from their stereos.
Please feel free to interpret, 'cause i'm stumped.