This winter I have installed a long gennaker pole. It extends the forestay by 1500 mm to carry the gennaker of approx. 87 sqm (luff is 14.1 m foot 8.0 m)
Initially I have planned to make a conical carbon pole until I met an old friend from my dinghy days and finally bought a carbon pole from a 14 ft dinghy.
The max dia is abt 82mm, at the bow it is 70mm and at the end abt 55 mm, wall thickness is 3 to 4 mm, depending where you are.
I am using a dyneema bobstay of 5 mm thickness.
It was a bit scary when we fist sailed the boat at 16 kts and a TWA of 90°. The pole was flexing to leeward but did not break. Here you can see the gennaker in light wind.
There are 2 devices to fix the pole on deck. at the front I have used a metal ring from selden which I have welded to a 3mm socket with plywood underneath.
The fitting at the rear end of the pole is a bit more complicated. I intended to buy it from selden as well but the refused completely as they wanted me to buy the whole system. A good reason for me not to buy a mast from them !
The system is quite similar. I have used a Wichard padey, which I flip to vertical. Inside my selfmade fitting is a 10 mm bolt with a spring. This way I can easily lock the pole to the deck an with pulling the blue rope the bolt slides forward and unlocks the pole.
As I only paid 50 € for the pole the whole system was less than 200 €!
The halyard point was put upwrds by 0.6m just by rivetting another padeye below the exit. Seems to work.
Overall experience: The boat definetely deserves a bigger downwind sail. The gennaker is a lethal weapon between 80 and 140° TWA. Going deeper does not work as expected. I know gennakers from dinghies where you point higher to fill the gennaker. With increasing appearant wind you start bearing off.
So far my tp speed with the gennaker is 10 kts in 16 kts of wind at TWA 120°. To be improved.
If you want to use the spin pole then the performance downwind is much better.
I wished the boat was lighter!!!