if wind conditions are to light to plane a 93l board with a 5.8m sail,would a 6.3m sail make a differance
yes, it would definitely make a difference but very small ... maybe about 0.5knts.
so i would say marginally noticeable.
In marginal conditions I wouldn't be on a 93l board. I use a 140l board if the conditions are iffy. Firstly, it planes so much earlier and secondly, much easier to get back in when non-planning.
I actually think the sail makes little difference its more the weight of the sailor, now anything smaller than a 10m is not going to move me at all, the problem seems to be all the donuts Ive been eating.
Actually Im really hungry now
I was once given some good (general) advice when choosing a sail & board..."pick a sail for the gusts & a board for the lulls".
It basically means, pick a sail for the conditions, but if there are some big gusts, maybe drop a size for comfort & a board that will plane through the lulls. On a few occasions I've got it wrong & found myself either overpowered & tail walking in gusty conditions, or constantly dropping off the plane in marginal conditions, not quite able to keep on the plane to the next patch of wind - usually when I'm about 20m away from it!
Maybe I need a red sail!?
This winter I added a 6.4 to my quiver. My biggest sail prior to that was a 5.8. So glad I got the 6.4. Without it I would have hardly done any sailing at all. It just wouldn't have been worth it with a 5.8. Now I am looking for a 7.5 (for more speed).
So yes 6.3 vs 5.8 makes a big difference in marginal conditions.
I also got a bigger board for the light days (85L - 111L) and that increases the fun factor again. Earlier planing and less slogging.
I am under 60KG, so if you are heavy 5.8 - 6.4 wouldn't be such an improvement. I'd suggest 7.5, but it depends on whether you think you and the board can handle a sail of that size.