Tuesday, April 12, 2022

Do the Math (the First Time!)

My wife has been encouraging me to figure out why Gardens seems to have a mind of her own in light air: poor tacking; failed tacks; turning slow circles without regard to the helm. It was frustrating to me and anxious/scary for Jan. 

I had no answers... until last Sunday. I had an apostrophe.*  

Gardens' centerboard up-haul system is not as designed. I didn't like the block/tackle rig as shown in the plans. I designed, developed, and built a 4:1 block system contained in a box on top of the centerboard case. 

On Sunday it occurred to me that the 4:1 system was self-limiting; the centerboard could swing part way down. I pulled out the plan sheet showing the centerboard extended vertically; used a compass set to the length of the 4:1 system; drew an arc from the aft end of the system - and realized the centerboard could only extend through a 45ยบ arc - or about half way! I suspect this limitation had something to do with the boat handling issues we experienced, particularly in light air.

Yesterday, I removed the cap and box, removed the 4:1 set-up, and re-rigged the up-haul to a 2:1 system which is limited only by the length of the up-haul.

I did part of the math when I put the system in place, just not all of the math.

* Bonus points if you remember/understand the "I had an apostrophe" movie reference. 


  1. HI Bob, How lucky that I happened on this post today. This weekend I am about to start work on my pathfinder centerboard lifting mechanism, and I had been planning to use your 4:1 design-- Now I'll switch to 2:1. Thanks for writing this up.

    1. Hi Andrew, Glad my mistake helped someone avoid making the same mistake. That 4:1 system was smooth as silk - but it didn't do what I wanted it to. 2:1 will (should) be just fine (I hope to get the boat on the water soon).