#floatplanes

To answer this one, i have to get into a bit of etymology - the precise meaning of words and their study. ‘Seaplane’ and ‘floatplane’ are words that most people use interchangeably, but they are meant to have distinct meanings.

A seaplane is, technically, what we more commonly call the flying boat - a hull that lands on water (regardless of whether or not it can be an amphibian). A floatplane sits on floats or pontoons, and which word you use for what plane depends on how you define those terms, as well. They also can be interchangeable, but also slightly different.

But ‘pontoon plane’ is commonly used to refer to floatplanes of all varieties, and I’m going to take a stab in the dark that this is what you meant. So after all that parsing of word meaning (and educated guessing!) I’m going to give you an actual answer, and that’s the Fabre Hydravion of 1910.

There were aircraft built on floats of various kinds before this, of course - there were powered examples that failed to fly, and unpowered float-based kites, but the Hydravion was the first to accomplish the job successfully.

(Photograph courtesy of Wikimedia Commons)

As you can plainly see from looking at it, the word ‘airplane’ might appear to be only vaguely applicable - but it is important to remember that the first decade of aviation design went forward with nobody having a very clear idea what an airplane ought to look like. Nor for that matter could anybody really agree on how it should be controlled, powered, or what its purpose should be.

This is the time of Those Magnificent Men in their Flying Machines, a strange and vanished world that is almost comical to our eyes. But while it looks whimsical, it was a time that moved fast - the French built the first military seaplane tender only a year after the Hydravion flew. The first purpose-built seaplane carrier, HMS Ark Royal, came only five years after, with aircraft that were already a generation further along.