In a practical comparison, a folding propeller shows what it can do better than a fixed propeller. The YACHT article also answers the much-discussed question of whether the not inconsiderable investment is worthwhile and which propeller is the right one for your yacht.
When it comes to propellers, there is often disagreement. Some rely entirely on the whisk with fixed blades. The Fixprop is considered reliable, has a high degree of efficiency, is also relatively light and favourably priced. The only, but all the more significant disadvantage is that it slows you down when sailing, and not just a little. This is because its propeller blades generate a noticeable drag under water, regardless of whether the drive is turning or blocked.
Only the so-called folding or rotating blade propellers are able to reduce this significantly. The blades of these mechanically complex and therefore expensive props fold or turn into a favourable position when sailing due to the water resistance. Regatta sailors or those with sporting ambitions will not want to do without them. Cruising sailors also benefit from a considerable gain in performance under sail and, with the right prop, also under motor.
But how big are the differences in practice? How efficient is the folding propeller as a counterpart to the fixed-wing propeller? YACHT wanted to find out exactly and accepted an invitation from Danish propeller manufacturer Gori to Stockholm for a direct comparison. Two completely identical Jeanneau Sun Odyssey 39i sailing yachts were provided as the basis for the comparison. Both boats were the same age, equipped as standard, of the same weight with empty water tanks and each powered by a 39 hp built-in Yanmar diesel with roughly the same mileage. The comparison was carried out in the calm, wave- and current-free waters of the Stockholm archipelago. The best conditions for an objective test.
