www.seabreeze.com.au/forums/Windsurfing/General/cutting-down-mast/Apparently last time I said this it was the worst advice on the internet, so I'll try it again :
If your mast is worth more than $1 then don't, trade it in for a 430
If your mast is worth < $1 and if it gets you on the water when otherwise you wouldn't, then yes, cut it up.
For the sail to perform badly it first has to perform.
If you are just uphauling and wobbling along and you don't have pressure in the sail, then the sail can't perform badly because it isn't performing at all.
If you rigged a sail on a drain pipe then stood blindfolded and stationary in a shed, could you tell the performance of the sail is compromised ?
I learnt to windsurf with a bed sheet tied to a broom stick. A cut down 460 will perform better than that.
Once your mate can sail along, jibe / tack, beachstart and uphaul then start worrying about sail performances.
If this is still the worst advice on the internet then I will go cut down an old mast, sail it and post the video. If you reckon I sail worse than somebody who has never sailed before would sail on a correct mast then I'll concede the above is bad advice and never offer it again.