A band of pirates arrived on the congenial island La Orchila looking for the treasure of the pirate Blackbeard. They had a rough map of the location stolen from a museum in London.
In a well-protected dell with a small spring, they saw a tree with the following markings placed in a band around it:
After scratching their heads and other parts and arguing amongst themselves, one pirate suddenly saw the light.
What was the message on the tree?