Notify of
Inline Feedbacks
View all comments
Jeff Eschman

The pumping is caused by vortex-induced vibration. If the sail is down, you can also prevent it by simply wrapping the job halyard around the head foil.

You can see the same “engineered” solution on industrial smoke stacks with helical fins/strakes running down them, and even on older automotive whip antennas with a spiral rib.

Michael Jack

Hi, John. Would this work for a boat in a fixed position? Just about to pull the boat out for 6 months and I am quite concerned about the headstay pumping. The Baltic winter storms can be ferocious. I guess Jeff’s solution is better in thus case (but I assume he meant jib rather than job)? Any other hints on this subject?

Michael Jack

Thanks, John. I had indeed read your comments on taking the mast off (I have read everything on your site multiple times since I recently joined). But due to the global economy tanking, I need to keep the costs as low as possible. I even considered leaving it the water but decided against it due to the possibilty of the sea freezing. I will try Jeff’s solution.