The other day I was in the Long Beach area with my camera and I was lucky enough to catch a full caorlina go by in one of the Naples canals.
Caorlinas are common in the Veneto, but only a few exist here in the US.
Of course the caorlinas in Venice are different from the ones here.
The ones in Italy are narrower, lighter, and used almost entirely for recreational rowing, I've yet to see one laid out for passenger service,
but the ones in this country do take passengers.
In fact they were redesigned to do so.
It's a lot more boat to row, especially when it's two guys rowing a full load of passengers, but the guys in Alamitos Bay seem to have no trouble doing so (and they do it while entertaining the folks on board).
The American passenger caorlina is a fairly unique incarnation of the boat, but like so many designs in other parts of the world - she was designed to serve a purpose particular to the region, and she does it well.