Comments by "Roger Smith" (@rogersmith8339) on "This Genius Propeller Will Change Transport Forever" video.

It would be interesting to see how these would work on sailing yachts at the lower speeds. The other thing might be the affect on prop walk going astern.
3
@MalcolmMacPhail Folding or feathering props tend to be best suited to racing type yachts where they do offer less drag. The problem is they are very expensive and depending on your keel arrangement, on cruising yachts they don't reduce the drag that much. The biggest issue with many sailing yachts is going astern (backwards) where the prop acts like a paddle wheel and pushes the back of the boat to one side. Not very helpful in tight moorings!
1
@MalcolmMacPhail Our last yacht was a Barbican 33 with a long keel so a folding prop would not have helped much (BTW, when you got the hang of her, going astern was not much of an issue. Our current 40 long finned / Scheel keel yacht is a pig astern! I know some folding props are very good at reducing prop walk, but our neighbouring boat had one that did the opposite, but it is a bit of a racey boat.
1