Short answers, pulled from the story.
Navigators in the Marshall Islands created stick charts by recording how waves interacted with islands hidden beneath the horizon. These instruments mapped wave motion and direction to help communities settle distant islands without modern technology.
The Song dynasty Chinese adopted the compass for sea navigation during the 11th century. Widespread open-seas navigation using these instruments began in the 15th century when Portugal explored the Atlantic coast of Africa starting in 1418.
John Harrison developed an accurate marine chronometer known as the H5 model from 1772. This device ensures precise timekeeping for calculating longitude and currently resides on display at the Science Museum in London.
Omega terminated operations on the 30th of September 1997. The system operated by the United States Navy promised worldwide oceanic coverage but declined during the 1990s due to GPS success.
The V-2 guidance system deployed by Germans in 1942 represents the first inertial navigation system. Submarines still rely on these systems because GPS reception fails while submerged.