Even with my Goodall spinnaker from 2004 I used blocks on the main beam. In the last few years to spi's have only become shorter in the foot.

"Do we need the pole at max length on these boats ?"

Actually, we never did. That rule was only included in the F16 rules to satisfy Texel and SCHRS handicap systems that have some formula that determines max spi pole length.

That formula is a pain in the neck and so I just took the virtual F16 with its mainbeam halfway the hull and worked out that like that we could have a 3.5 mtr spi pole and still not break the Texel or SCHRS rules. At that time, from comparisons to F18's, I already knew that we would be using shorter poles. Mine is actually 3.25 mtr. and seems to nicely balance the boat. I did try 3.5.mtr but the leehelm became a problem. I tried several intermediate positions as well, but 3.25 mtr worked best and then I still have to place my last blocks on the main beam. This does clear up the area around the side stay though (an unexpected benefit).

I'm still convinced that 3.50 mtr spi poles are too long for F16. I mean, you can sail with that, but the optimal length both balance and speed wise seems to be less then that. Remember that our forestays are relatively far back as well, partly due to the use of bridle struts that makes our jib foot come out very low. The slot between the spi and jib luffs is pretty big already on F16's. Equal in size of larger then the ones on F18's.

I recall that Blades, Falcons and others are using less then 3.50 as well.

Wouter