I agree with Ron, who never fails to amaze me with his incredibly well-hidden intelligence...............
The terminology is all over the place, and will probably never be standardized or straightened out. For instance, in England the only kayaks that are called kayaks are traditional skin-on-frame jobs like Nanook might be dodging ice floes in. My Nordkapp or Outer Island, which we'd call a sea kayak, would be called a canoe over there .... unless you're on the Valley or NDK web site, where it suddenly becomes a kayak once again. Why? Well, perhaps the fact that us Yanks account for twenty or thirty boat purchases from them for every one sold to a local bloke might have something to do with it. Just a wild guess.
Pirogue means boat in French. So does bateau. I don't speak French except when in a foul mood, so don't ask me what the diff is. All I know is that pirogues are simple canoes, and are called pirogues because they were pretty much invented by Cajuns, who are like French exiles or something and speak a strain of French that nobody can understand, even in France. But then, nobody can understand a word they say when they attempt English, either, or even Texan. Fortunately, they get their ideas across in spectacular fashion through food and music .... and boats. No problem.
Some people call the rotomolded plastic SOT a kayak, and that's a stretch. Well, the operators generally wield double paddles, but there any similarity ends as far as old Nanook might be concerned. But what else would you call them? They're so repulsive that no self-respecting original name will have anything to do with them, let alone stick, so kayak it is.
So we pretty much just mix 'n' match, and use whatever feels about right at the time, and nobody ever calls the name nazis on us. We get away with murder in paddle sports.