Just need to get my head around the theory of out of spec mast lengths. What happens with a sail's rigging effort, performance and feel if fitted with a too long or too short mast with extension? I know there could possibly be more variables involved (eg. sail design) but generally what would be the result? Uses are non racing.

Here are 2 examples for 2 different size sails using the same mast (460/25);

6.4 - If a sail maker recommends a 430/21 or a 460/25 as an alternative
8.0 - If a sail maker recommends a 490/29 but one uses a 460/25 with correct extension

Does carbon content in a mast make a difference in stiffness?

Thanks.

It depends on what type of sail aswell, race sails are pretty specific to what mast the rig on. where as freeride and wave sails without cambers are a bit more forgiving.. but in saying that i don't mean a certin brand of sail on a different brand of mast.

For example, i use Severne sails, so being a heavier guy, i have rigged my 5.0m Blade on both, a 400 as being the proper mast and then on a 430, the sail rigged very similar on both masts but because the 430 was stiffer the sail had more power in it's lower wind range, but this was due to the sail not twisting off as easy but i would say it lost a bit of the higher wind range again from not twisting off in the head.

This would also go the other way, if you run a softer mast, say 400 instead of 430 on a sail intended for a 430 the sail will be softer, twist off alot morewhen powered up, and be less powerfull than intended..

If a mast say from Pryde mast says it's say 460/25 100% and a constant curve and a Gaastra says the same, don't mean they are the same mast and will rig the same..

Higher Carbon content won't make it stiffer but it has better memory so be will more responsive, feel crisper...