The Rheinschwimmen (swimming in the Rhine) has become a long tradition. This year, for the 33rd time, thousands will swim/float down the Rhine.

Beware, this might look very easy, but one should not underestimate the Rhine. I highly recommend being able to swim 200 meters without using any swimming floats or similiar means.

There are many places to buy a bag, which keeps the clothes dry:

http://www.slrg.ch/de/nw/sektionen/basel/rheinschwimmen/schwimmsack/bestellung-schwimmsack.html

I also do highly recommend, that you wear some kind of protective footwear. There is the risk of broken glass, so wear something which would protect you from them (plastic sandals).

http://www.slrg.ch/de/nw/sektionen/basel/rheinschwimmen

PS: I also will go Swimming in the Rhine some times before and after the official Rheinschwimmen. Especially, when it is very hot, I like to go during lunch break. If you want, you can join me, just send me a message, if interested.