brilliant youtube review of the blue dial just stumbled across~fantastic yachtmaster/rolex historical context and stunning closeups of all elements in their respective glory ~ (spoiler alert) the kipper's knickers as duly summed up... enjoy
https://www.youtube.com/watch?v=RkUr8EbVEUo
https://www.youtube.com/watch?v=RkUr8EbVEUo