Some things are really hard until you see the easier path.
Barnacles have glands that “secrete a type of natural quick cement able to withstand a pulling strength of 5,000 pounds (2,000 kilograms) per square inch and an sticking strength of 22–60 pounds (10–30 kilograms) per square inch.” (Barnacles, Wikipedia)
In plain English: If you try to pull Barnacles off you will need an immense force. It would likely cost thousands of dollars just to rent the tools to do it.
Or you could just scrape them off.
Sometimes it’s worth taking a step back to get a different perspective.