Start with the engine HP and prop speed at maximum revs. Also need the shaft diameter. Then go to a prop specialist for a selection. They typically had an 18hp Bukh so that might give you some ideas.
I suggest that the authorities need to pick up on these tragedies and provide information on the dangers of putting to sea, or bar crossing, at the same time as the move-on orders. A simple hand out could save lives. A note to say that the vessel does not appear to be safe for sea passage might make the owner think.
Super hi-tech stuff. But is it in the tradition of the America's Cup? OK, still the preserve of the super-rich. Maybe we should get the billionaires to race their super-yachts. IMHO I would rather see the old rule 12m boats thrashing it out on an enlarged course which included real offshore weather.
Slight mystery- photo of the yacht leaving Yamba does not show the dingies. That bar looks awful! The whole situation was suicidal ignorance. Poor guy. Poor rescuers. So sad.
