I carry one...
for docking along side a wharf at locations with ugly pilings. It's a Cetol'd spruce 2x4 4 foot long, with polyvinyl end pieces made for standing it off a hull. Two lines centered down the verticle face to tie it off on the life lines or toe rail. Most effective when centered on the piling on the outward side with two large fenders placed near the ends between it and the boat, with dock lines made snug to hold the boat against this rigging against the piling.