Yeah, I do confirm that. In 1992 and 1993 I saw a Catalina PBY (I think it even had the "goldfish-bowl"-windows) at Wilson.
I didn't know who owned it or what it did; now I wonder what happened to it. For sure it wasn't 5Y-registered, because the kenyan roll of that tine doesn't show any such plane.
Up until the early 1950's, seaplanes were a very common sight allover Africa. They were only gradually replaced by airliners after WW-2. I saw a photograph of a DC-3 on floats on lake Tanganyika, dated 1968, only recently.
Nowadays there may be the occasional Cessna on floats somewhere, but certainly not on a big scale.