A photo from a time (1940) when a floating bridge was a triumph:

The first I-90 floating bridge, as photographed in 1940.
  • Washington State Archives, used with permission
  • The first I-90 floating bridge, as photographed in 1940.

Known as the Lacey V. Murrow Bridge, it was the largest and longest floating bridge ever built at that time, and it was the first to be built with reinforced concrete... When it opened, the bridge represented one of “engineering’s greatest triumphs,” in the same category as Boulder Dam and the Golden Gate Bridge.

It's hard to be a floating bridge these days.