In this picture, the hole for the tunnel has already been cut and the grippy is being attached. I prefer to orient it so the seam in the grippy is on the aft edge of the sprayskirt.
It is difficult to exactly anticipate the required length for the Grippy Strip, so start with a little long and then trim it to length as you complete the gluing of the strip to the deck.
The Tunnel is glued into a tube
The Tunnel is glued to the Deck. The outer surface of the Tunnel is glued to the bottom surface of the Deck with a 1/2" overlap. Index marks are put on each piece to help align the deck to the tunnel and make sure you finish the seam evenly.