IF YOU WANT TO START an argument among sailors, all you have to do is ask whether a sailboat will go faster with its propeller locked or freewheeling.
A few Christmases ago I started one of the longest and most controversial threads on the Cape Dory bulletin board. I explained that Santa had just brought me a toy helicopter, and while I watched it fly around the room and crash into things it occurred to me that if the engine stopped, it fell to earth in two different ways – very quickly if the rotors stopped turning, and much slower if the rotors continued to spin of their own accord. I therefore concluded that a spinning, freewheeling propeller on a sailboat would cause more drag than one with its shaft locked.
I naturally cited several marine authorities who agreed with my theory but it didn’t silence the many Cape Dory critics who were surprisingly adamant that they, and they alone, were right. The Righteous Freewheelers, I call them.
Now, however, I have stumbled across more support for proplockers. I found it on a website at http://www.pelaginox.com/, which I believe is a British-based data base for a whole host of useful facts and figures for amateur sailors. I quote:
“Incidentally, some feel that drag with a spinning prop is less than that from a locked one; but consider the case of the helicopter. If the engine fails, the pilot performs an ‘autorotation’: the gearbox is taken out of gear and as the helicopter falls, air resistance causes the rotor to spin, and the machine achieves a stable descent attitude and a much-reduced rate of fall — the high drag from the spinning rotor allows it to land with a parachutic descent, albeit heavily, whereas with the rotor locked it would simply fall out of the sky. You can check this if you have a mechanical-shift gearbox (or a shaft brake) — test your speed with or without your prop locked; you’ll sail faster with it locked.”
I don’t know who to thank for those extremely wise words, but thank you anyway. I knew I was right all along. Proplockers rule!
You will find that the truth is often unpopular and the contest between agreeable fancy and disagreeable fact is unequal.
— Adlai E. Stevenson, NY Times 9 Jun 58
Boaters’ Rules of Thumb, #38
Compass cards. Small boats don’t need compass cards with markings of less than 5 degrees. It’s very easy to estimate the positions of single degrees between two markers 5 degrees apart. It’s not often that you can steer accurately to within less than 5 degrees on a sailboat in any case.
“How’s your wife getting on with her cookery lessons?”
“Man, her fame is spreading. Last night a pygmy from the Congo called and asked if he could dip his poison arrows in her stew.”