Hi Wayne, it was a hire boat service in Mordialloc, but I don't recall the business name. It could easily have been Pompei. I was more or less used to a Seagull outboard at the time, and the low RPM, oddball starting method (turn the flywheel with the flat of the hand), and generally sluggish thudding of the Simplex didn't turn me on. It would probably have outlasted half a dozen Seagulls on a fraction of the maintenance, which was why it was in a hire boat, but it was a fairly huge object for its miserable power output. If I'd been hiring out motor boats in the late 1950s I'd probably have been putting Simplex engines in them myself, but privately-owned boats seemed to have Ford 10 (i.e. Prefect) engines, and they were a good bit smoother and more powerful.
