3200mm +/- 5mm [125 inchs - 10' 6"] if you want to be class legal for the special youth events. See the
Hobie class rules .
If you aren't going to be sailing class with the pole then you need advice from a H16 sailor who has already fitted a spin. Too short and you close the slot between spinnaker and main. Too long and the boat will have excessive lee helm. The length specified in the Hobie class rules sounds reasonable (much better than the Hobie factory advice of 8.5' on the Hobie 18 which is way too short).
If you will be sailing in portsmouth class (forgive me, I don't know if the Portsmouth handicap system is used north of the border) then it doesn't matter what pole length you use - the portsmouth number correction will remain the same at 0.96.
Chris.
