I noticed on "Show us your Redbay" Willk's rib has fenders out against the jetty and the humber next to him. (The humber i understand as Willk may not want one to touch his Redbay!

) But is the point of a Rib, especially if specced commercially as Willk's is, often with extra rubbing strake etc etc that you don't need to faff with fenders like with hard boats.
Just a thought, we never bother as if the jetty/slip is that barnacle covered and the swell is large, no poxy fenders will prevent damage anyway. You would hold the boat off and not leave it there in the first place. As with Ronin's crew in the "IOM last year" photos from Tony T.
If in a harbour where it's calm etc, no damage will occur.