Nathaniel Bowditch (ˈbaʊdɪtʃ; March 26, 1773 – March 16, 1838) was an early American mathematician

Mathematician

A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 remembered for his work on ocean navigation

Navigation

Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...

. He is often credited as the founder of modern maritime navigation; his book The New American Practical Navigator, first published in 1802, is still carried on board every commissioned U.S. Naval vessel.
Nathaniel Bowditch, the fourth of seven Bowditch children, was born in Salem, Massachusetts

Salem, Massachusetts

Salem is a city in Essex County, Massachusetts, United States. The population was 40,407 at the 2000 census. It and Lawrence are the county seats of Essex County...

.