Broad Reaching and Running – 120 degrees and greater
With the spinnaker set for a broad reach, the trimmer eases the sheet until the luff curls and checks the curl is even from top to bottom. The guy trimmer should check that the pole is at 90 º to the apparent wind – a telltale attached to the topping lift, some 50cm up from the pole itself is a great help. The sheet and guy should be adjusted to suit the conditions and the sailing angle – but never independently from each other – this is slow and can end with one trimmer fighting the other with the sail never getting the chance to settle down. The guy should only be trimmed at the sheet trimmers request.
If the pole is overtrimmed (too far aft) then:
The foot of the spinnaker will be hard against the forestay. The vertical seam will tip to leeward. The sheet trimmer will struggle to keep the luff curl under control. The boat slows down.
If the pole is undertrimmed (too far forward) then:
The vertical seam will tip to windward. The sheet trimmer can let a lot of sheet out, and the leeches can come together making the sail fuller therefore projecting less area to the wind. The boat slows down.
Keep the vertical seam vertical, and the foot of the sail away from the forestay. The pole should be as far aft as you can to keep to these rules, whilst projecting the max area. The spinnaker will be in front of the boat, and not pushing sideways causing heeling and weather helm.