Performance in regatta of staysail Dear Professor, dear All,
I m trying to optimize my sail plan for regatta regarding also the cost of sail.
Solano, a swan 44 has a great genoa on furler so i do not want to invest for a new one. It could be used between 8 to 21 knots with a good shape.
The question is what could be the result to use a medium staysail above 20 knots with the roller genoa fully rolled up above 20 knots in regatta ? (speed, angle, balance of the boat)
Dear César
This is an interesting approach.
In winds around 20 knots and over the boat can be expected to heel less with a jib, and be a little faster on the wind. One possibility for finding out more about this is to run ORCi test certificates with genoa respective jib, and compare the results. The certificates are expected to show the transition point when the jib becomes the preferred choice, but results in over 20 knots of wind are not available.
I can do this comparison for you if it is helpful, pls confirm that you have the tall rig I = 57.5 ft
Kind regards
Lars
Thank you very much for your answer.
Solano have a tall ring.
If i go for it i will share my experience on the forum to confirm your calculation.
Best regards,
César
Dear César
Enclosed pls find a comparison between genoa and jib in upwind conditions. It can be seen that the transition point is at 22 knots of wind with the assumed size of jib. Over that wind speed the jib will be faster.
The jib I-measurement in the calculation is 11.85 m, J and LPG is 4.03 m. If the jib size is larger the transition point will move to a lower wind speed.
Kind regards
Lars
Dear professor,
could you please give some more detail on how to interpret the graphics? I am not sure I understand its meaning and how you conclude that 22 Kts is the transition point while its out of range...?
On Soeur Anne 41/022 we tend to use our jib (very high aspect ratio : solent) between 25 and 40 Kts, and are always very impressed by its efficiency, especially upwind of course.
The only difficulty is changing at sea without waiting before the wind and sea get too strong!
Bonne chance César! Gib plus removable headstay are indispensable on our mistresses, even for cruising!
Kind regards.
Philippe
Dear Philippe
The upper line shows how much slower the boat is with the jib compared to the genoa in seconds per mile. The genoa is the base meaning that it defines the zero level. In 6 knots of wind the jib would be 240 seconds slower, but with increasing wind speed the difference is reduced. By extrapolating it can be estimated that the jib line crosses the zero level at 22 knots, at higher wind speeds the jib will then be faster on elapsed time.
The lower line shows the compensation given by IMS if the jib is declared the only headsail for racing. The line crosses zero at 16 knots, and in winds over that the jib would be faster on corrected time.
Pls feel free to ask if something is unclear
again thank you lars for this very interesting graphic, i m quite surprise about only 22 knots, it could be interresting to design a little big jib...I think i will go for it and let you know about performance. Philippe j'espere à bientot pour une petite virée avec soeur anne et solano.
