The previous owners (or one before that) of Sonas added a neat feature to the boat.
For those who sail or used to sail, you will recognize the sheet tracks that have been added to Sonas along her length. These are simply awesome for placing fenders at the right location. Because each track has two moveable eyes the fenders can be placed vertically or horizontally.
I had never seen this on a power boat before so don't know if doing this is popular or just a brilliant idea!
That particular fender doesn't have it (or didn't then) but each fender has a swivel tie snap so you just clip it onto the eye, then adjust the rope length using a know under the swivel eye. You can just about see one on the forward fender.