So, you find yourself on a strange pier in a strange marina and soon you are scheduled to teach a class on a strange mono-hull yacht with a single inboard engine. Your boat is docked in a slip in a “tight” marina where there isn’t much space between piers to undock. Boat owners in adjacent slips tend to enjoy cocktails in the cockpits of their boats more often than they actually undock them. Several of them are present now. Finally, you notice a brisk breeze blowing onto the stern of your boat, and you realize it may be necessary to back your boat all the way out into the fairway located more than a dozen slips to port. And all those other boat owners will be watching!

You know all about propeller torque or “prop walk” in reverse gear and your boat probably has right-handed shaft rotation in forward gear, but given all the described conditions, it would be nice to know for certain. Opening up the engine compartment, you find that the shaft itself is not easily visible to check the direction of its rotation. But don’t dismay. I have a tip for you to determine a boat’s prop walk that is more useful than just knowing whether the prop on your boat is right-handed or left-handed.

Locate the key, turn on the engine, check the wet exhaust, and leave all dock lines fast (securely tied) to the pier. Throttle down, then shift the transmission into reverse. I like to wait until the stern lines and/or forward spring lines are taut, and then I gradually throttle up about halfway. After confirming that all the dock lines are secure and holding, look over the rail on both sides of your boat. The prop wash on one side will normally be more pronounced than on the other side. The side with less water turbulence is the side toward which your stern will “walk” or move when you undock in reverse gear.

You can also surmise how much prop walk you will experience. Look again at the water on the more turbulent side. If the prop wash is mostly forward of the beam, your prop walk will not be that dramatic. But if the prop wash is mostly aft of the beam, Newton’s Third Law will move your stern markedly in the opposite direction of all that thrust. Your boat could be a “spinner”!

Look at these photographs of a Catalina 36 yacht docked in a slip with the engine running in reverse gear at just less than half throttle. 

The photograph above (with the white fender) is the port side. Notice how calm the water is there.

 

The photograph above (with the black fender) is the starboard side, aft of the beam. Just by looking at this thrust turbulence, I know that this boat’s stern will move to port in reverse gear, more than a little, but not a lot. One club I know ties colored fenders on its boats on the sides toward which the stern walks in reverse.

Propeller torque in reverse gear is a mixed blessing, but the silver lining is that you can always inform yourself of your boat’s stern walk before actually undocking. And remember, prop walk disappears when you throttle down and shift back into neutral. Finally, whenever you throttle down, wait another second or two for the engine rpm’s to die down before shifting into or out of gear.

Your ASA students no longer have to evaluate you, your course, and your school on paper.

ASA student surveys have been integrated into our new computer system and can now be submitted online by students when they log in to their accounts at the ASA website.

When students log in, they will see links at the bottom of their “Welcome Membership Portal” page. There is a link to a student survey for each ASA course in which they have earned certification since the beginning of 2017.

As an instructor, please urge your students to log in to the ASA website regularly for our latest sailing information. Ask them to find, complete, and submit these new electronic surveys. Each survey only requires a few minutes to complete.

Students new to the ASA will receive an electronic “Welcome Letter” with their username (ASA number) and a temporary password that will allow them to access their accounts.

Give your students more of a challenge

Sailing Challenge has been updated with lots of great new features and challenging courses. So tell your students to download ASA’s Sailing Challenge App and have your instructors check out ASA's lesson plan for ideas on how to incorporate the Sailing Challenge App into their classes.