Hi Seve C and Doby:
For Steve C.
Yes, virtually all sail designers do sugggest "alternate masts".
I often use "alternate masts" (esp. with the Sailworks Huckers) as this can change the characteristics of a sail quite a bit.
I guess my "point" has been missed here somehow.
If you check the link in Post #2, you will clearly see that North "specifies" a particular mast as the "best mast" (with the little slashes whatever they mean) but is also very specific on the range of
IMCS stiffness numbers.
The chart also lists the "best"/and suggested alternate length masts and it's pretty clear to me that they designed each sail around a particular mast.
So, you what the full performance that the designer had in mind...?
Or do you want to save some money and get something other than the full performance. It's your choice, and can be influenced (as you suggest) by sailor weight, ambient conditions, sailor style, and discipline you are most interested in (i.e. speed, racing, B&J, waves; or freesailing.
Here's the link for the ICE (a different breed of sail than the Daytona for sure)
As you can see, the "best mast", and the range of IMCS stiffness numbers changes as the sails get larger.
Have you ever tried your sails with the recommended best mast?
Try to borrow genuine North masts that are specified as the "best mast" for your sails and let me know what differences you see in how they rig and how they feel on the water.
I'm pretty sure you will both see and feel a noticeable difference.
Might be better, might not, but only you can make that decision.
Upgrading to the "best masts" might be a good thing, and maybe it won't make enough difference to justify the cost. Again your decision.
I'm reasonably sure that the designers of the Daytona and Ice sails had a particular mast in mind, that they used to develop and test the sail.
Marketing then came along and pretty much made them put "alternate masts" and IMCS numbers in the chart, because that's their marketing program.
No one knows if they ever tested the sails with both the "best mast" and the "alternate mast" side by side.
Hope this helps,