317" = 26'-5", hobie web site lists the Hobie 16 mast at 26'-6". However I don't know if that includes mast head or not. I don't own a 16, so I can't give you measurements.

The screws in the side of mast means your mast was definitely converted with with one of the original comptips which were shorter. The current masts don't have the screws in the side of the comptip- the comptip is secured by the rivets for the mast tang (and glue). If you don't have someone nearby with a mast you know is good, then email Hobie to get the length of the mast (without head cap and mast base).

On chopping the comptip, you may want to get a second opinion, but in my view it would be totally class legal. Again, you may want to contact Hobie to find out if there are any structural issues, or if it will be difficult to reseal, but ruleswise, you'd just be putting the boat back to 1986 spec (the comptips were shorter then).

Bottom line- make sure the mast is actually too long because it's ok that the aluminum section is longer than on new masts.

sm