Robin. Thanks for your reply. When the problem ocurred, I consulted several Yanmar dealers who all said the gear box would be damaged by swapping the morse controls on the basis that the gears are designed to resist the forward thrust in ahead and vice versa in astern. Yanmar website also said that the propeller direction for the gear box was RH. It was on that basis that we felt the only sensible solution was to replace the propeller. I’ve since discovered that the gear box is actuallu bi-directional so we could have just changed the controls. You don’t find that information on the various websites.
By the way, we have met before. You very kindly took us out for a trial sail in the Solent 2 years ago, arranged by Clive Stratton. You were, at the time, considering selling your boat but clearly that has not yet happened. We found Senitoa in Scotland in late 2018 and kept her on the Clyde until last autumn when we brought her to Holyhead, planning to move to the South coast this spring. Covid put paid to that so it’ll probably happen next year. Regards, Andrew