You will be repaid a thousand times for whatever effort you expend to have your navigational equipment complete to the smallest detail.
"Lectures in Navigation"
Ernest Gallaudet Draper
He cut every corner he knew, used every trick of navigational skill he had ever learned.
"The Instant of Now"
Irving E. Cox, Jr.
Seamen had access to compilations of Arab mathematicians and astronomers and to navigational manuals and technical works on the science of navigation and the instruments necessary for precision sailing.
"Our Legal Heritage, 4th Ed."
S. A. Reilly