Bill I think your talking about this thread.
Hey some advice. The thickness of the interior is diffrent at diffrent locations. Example the Bow has thicker foam. So the spacer you need to make /install with be thicker in the bow than in the side pannels. Just make sure the thickenss of the space matches the tinckness of the foam and your speaker.
Be sure to account for enough room so that when you tuck the vinyl back in and glue and staple the vinyl back to the spacer that you made enough space so the speaker fits in and around the hole real tight. Look at the pictures and let me know if you have anymore questions. If you have skill's with the Jig saw this is a easy project. You can do the whole boat 6 speakers in 1 day http://www.wakeworld.com/MB/Discus/messages/65921/423605.html