Twenty years later, he was the first to describe how an accurate clock could be used to determine longitude.

More than one European government offered a generous prize to the first person who could accurately determine longitude.

To know a ship's position at sea, it is necessary to determine its latitude and longitude.

This type of tags relies on light levels to determine latitude and longitude.

We don't know how well they knew to determine their latitude and longitude.

He was the first to use a marine chronometer to determine longitude.

Click here for a list of sites to help determine your latitude and longitude.

For most of history, mariners struggled to determine longitude.

The navigator can then determine longitude without a marine chronometer.

What method did they use to determine longitude each day?