Eric,
We have 2 H20s w/ Inter 20 spinakers at the club ... Soon to be 2 more. What we found is that the tip of the pole (only 13 1/2 feet long with snuffers) sits about 16 - 20 inches above the horizontal plane of the decks with probably 2-3 inches of prebend only. "Tip of the pole" = attachment point of the spi tack on the snuffer ring, afterall this is what is important.
The bail(sp?) is roughly 37 inches from the top of the mast(standard H20 31' mast). The trick is to hoist the spinaker up to its desired height(all the way :-) for an I20 chute) and adjust the pole height such that you can grab the luff with your fist and give it a half a twist.
Hmmm, not sure if this is clear enough ... I'll look for pictures I can send/post.

Do you need a snuffer ?

Another thing DON'T put holes in the bow, attach to the bridle chainplates.

To Mike... Mike, you have years experience on H20s over me but I think a 15 foot pole is enough to throw the ballance off on any 19' beach cat. My concerns are more with the strength of the Comptip. Have you sailed in 20+ knts with the chute up on your H20 ?

Marc