Modification to height of mainsail on a Storm 15

[Terry Cross]

We intend to fit a sprayhood to IONA which would require the maisail to be raised by a further 180mm.
I hope to acheive this by moving the halyard take off point 180mm lower on the yard and, to keep the sprit horizontal, move the turks head 180mm up the mast. I have already lengthend the bottom of the yard by fitting side cheeks.
Will this move the Center of Effort too high?
Has anybody any comments?
Terry Cross

[Michael Rogers]

Hi Terry

I think lifting the whole sail as you suggest will, at least in theory, increase the heeling moment. Is the Storm 15's mast raked? - probably not as much as the Storm Petrel's. If there is any rake, the C of E (I'm not being liturgical here) will be moved aft as well as upwards, which might increase any tendency to weather helm. However I don't think 180 mm would affect either heeling or the balance of the rig all that much. The only thing to do is to try it. You could also try some water ballast?

Your crew (or you yourself, when you're not at the helm) will appreciate a spray hood, that's for sure. I hope it works out.