If your side rub rail is 'wavy', this might be why.

[SilentSeven]

Here's several screws I replaced on my 2004 206's rub rail to correct some waves in the alignment. PO seems to have liked to bump the dock on one side.

Thanks NautiqueJeff for pointing out bent screws are typically the issue.

Replacement screws are #8 stainless 1 1/4 inch. 1 inch screws also worked on my boat.

Easy to do when on the trailer and a warm day. Remove the aft rub rail finish plate. Pull the center piece out to expose the screws. Replace bent screws.