I've heard that it's not uncommon for blue-water sailors with small machine shops on their boat. One story was about a guy making a new cylinder for the diesel

I've heard that it's not uncommon for blue-water sailors with small machine shops on their boat. One story was about a guy making a new cylinder for the diesel engine on his lathe while being tossed around the cabin in a storm. That's a case where you need it right now and can't order it online :)