If you're interested in the subject, the book "Longitude" by Dava Sobel (mentioned in Resources) is a very good read with lots of historical perspective on how these clocks were built.
1. The realization of how much of the world has to be “invented.” Latitude and longitude didn’t strike me as an invention, but they are, and more interestingly longitude specifically is a conceptual invention that more or less had to sit downstream of a rather immense physical invention (Harrison’s clocks).
2. “The world has a surprising amount of detail”: as evidenced by looking at H1, H2, etc… there’s a lot you have to account for to achieve the apparently simple task of measuring time aboard a ship.
3. The social components to invention/discovery/progress: The competitions, funding/lack thereof, the need for “evangelism” around the different approaches, the need to find patrons (VC’s basically) to create a breakthrough, etc.
This book would make a great gift to an intellectually-inclined young person in your family!