Biography|Klaus Töpfer — The Wager Swim Under Mainz South Bridge

The image that stuck was a federal minister in a wetsuit dropping off a police boat.

The date was 14 September 1988.

Taz, writing from Mainz the next morning, put him on the water the previous afternoon, just after the Main flows into the Rhine.

A police launch took him toward the railway bridge between Mainz-Weisenau and Gustavsburg — the Südbrücke at Rhine kilometre 496.4.

He jumped in a diving suit.

Greenpeace met him on the Mainz bank with a banner that read Taten statt Baden, Herr Töpfer.

Süddeutsche Zeitung later recorded that he crawled downstream for about a quarter of an hour and that he spent the rest of his life insisting the swim settled a lost bet, not a water-quality certificate.

The bet itself had a paper trail in the Rhineland-Palatinate campaign: an SPD opponent had wagered that Töpfer would leave Mainz for Bonn.

The opponent was right.

Two years after the Sandoz warehouse fire sent poisoned firewater down the Rhine, a swim was still a stunt.

Taz printed the official readings at that reach — nitrate, phosphorus, chloride, mercury, cadmium, chromium — and noted a warning from the Federal Health Office the same morning.

Töpfer, the paper said, told imitators not to follow him in.

The Action Programme Rhine, agreed with the other riparian states, was already the real policy: cut the pollutant load by half in ten years.

The bridge is still the iron crossing on the Mainz–Frankfurt railway.

Stand on the Mainz towers and you are looking at the reach where a minister chose a camera over a press release.

The river is cleaner now than it was that September.

The photograph is why many Germans can still name the man.

Photo: Südbrücke, Mainz. Wikimedia Commons, public domain. Portrait: Rainer Weisflog, German Federal Archives, CC BY-SA 3.0 DE.