Old Fort Bay (YFT) to St. Paul's River (YSP), 7 statute miles with an Otter on floats. Or skis, depending on the season. Took about 4 minutes.
Connie that Tri-motor sched wasn't Port Clinton OH to some island in Lake Erie up near Sandusky, was it? They ran that with a Tri-motor well into the 1970's I believe.