Apps for Sailors: Spyglass
Traditionally, sailors have used a hand-bearing compass or rangefinder binoculars to take bearings on a mark, check the angle of an approaching boat to avoid a collision, determine their distance offshore, and monitor their anchor position.






![Ted_Turner_April_1985-Bernard-Gotfryd-2048x Photo from Library of Congress, Prints & Photographs Division, photograph by Bernard Gotfryd, [Reproduction number e.g., LC-USZ62-12345]](https://s3.amazonaws.com/media.sailmagazine.com/wp-content/uploads/2026/05/06145433/Ted_Turner_April_1985-Bernard-Gotfryd-2048x.jpg?w=1024)






