Originally Posted by
Hartington
I remember pitching up at an airfield next to a lake in Quebec and finding rows of floats waiting to be attached to aircraft currently using their wheels
I'm guessing you may have been there in the winter, when the lakes are frozen, so the floats have no purpose then, and as they add a considerable amount to drag they get taken off until the next summer.
As a side I would also mention the WIGE (wing in ground effect) "things" built by the Russians and affectionately known as the Caspian Sea Monster.
Not an amphibian at all, always operated off water (despite looking like an Ilyushin 76 jet on steroids). You can still see them on Google Earth, by the way, with quite good resolution, laid up at the sea edge over there (large one bottom right, smaller one top left).
42.881667,47.656667 - Google Maps