1. Pick a day when you're tied up to the dock with very little breeze.
2. Hoist the spinnaker to it's full height with at least one sheet attached and let the whole thing flap in the breeze.
3. Pull one of the clews into the mast and mark the spot where it touches - that's where (roughly) the ring needs to be.
4. The pole should be perpendicular to the mast so it will hold the tack of the spinnaker as far away from the blanketing effect of the mainsail.
A few ideas to cosider:
- A short sliding track is useful to adjust the pole height for different wind conditions.
- If you plan to rig the pole up the front of your mast, fit another ring up the top so you can clip the pole out of the way when not in use.
- If you pick a larger size ring than needed, you can clip your halyards to it.