Engaging talks for sailing clubs, yacht clubs, marine trade groups and boat show seminars
J. Seamus Duffy is a son of a sailor and a son of a compass adjuster, and runs the family business in Annapolis. He tells the story of the one instrument every navigator still trusts, from ancient China to the bridge of a modern ship.
Lodestone “south-pointers” in ancient China, Song dynasty sailors taking it to sea, the first European accounts in the 1100s, Peregrinus’s 1269 letter on magnets, and the birth of the compass rose.
How iron and steel hulls threw compasses off, and the fixes that saved them: Flinders bars, Airy’s correctors, Kelvin’s compass, and the liquid-filled compass that ended the “dancing card.”
Why new technology didn’t replace the magnetic compass, and why the Coast Guard still requires one aboard.
The practical talk: deviation, how compasses are adjusted, why your compass and autopilot disagree, the regulations, and a pre-departure checklist.
Length and format are tailored to your group. Q&A is always included, and hands-on compasses are welcome. Contact us about availability.