Fender bender

So that there is no fender bender
ships, not to bend, need massive fender.
And not to carry them around
they use them where they can be found.

For ferry boats it makes much sense
to install fenders big and dense.
Keeping the ship’s hull smooth and proper
old tyres are here used as stopper.

But pressed too hard they rub off black
no matter if used in a stack.
The practised captain therefore docks
carefully slow in ports and locks.