I have docked in a few places where fender boards would have been handy, but had to get by with just lots of fenders.
So... I decided to make up a fender board. I looked around the shed at home but only had pine 2x4's & 2x6's . Not strong enough I thought. I then found a 2"x6" piece of local hardwood I had cut up from a fallen grey box tree in the back yard. Grey box is the predominate native tree in this area.
I gave it a rough sanding, drilled a couple holes and spliced some loops, and it was ready to go. Simple! (or so I thought).
Before I tried it out, I lowered the board into the water, holding onto the spliced line. It kept going down. It sank like a rock.???
I researched the properties of grey box, and it turns out this is one of the densest woods in the world, Specific gravity 1.2 to 1.4. Equal to lignum vitae which was used for building stern tubes for submarines and rope block pullies.
Although my fender board won't break, maybe I'll make up another one out of something that floats, and save the grey box for a new stern tube.