Navigare necesse est

FAQ

What is Navigare Necesse Est?

Navigare Necesse Est is an independent maritime library dedicated to navigation, maritime law, nautical astronomy, maritime history and seafaring culture. The website brings together several decades of documents written by P.-A. Reymond, former merchant navy officer and naval architect.

Who is this website for?

The site is intended for professional sailors, recreational boaters, students, teachers, maritime history enthusiasts, naval model makers, and anyone wishing to deepen their understanding of the maritime world.

What topics are covered?

The publications include subjects such as:

  • astronomical and offshore navigation
  • nautical calculations
  • nautical charts
  • compasses, sextants and marine chronometers
  • RIPAM / COLREG regulations
  • international maritime law
  • territorial waters and EEZs
  • ship stability
  • maritime safety
  • shipbuilding
  • yacht architecture
  • nautical traditions
  • Vikings and maritime explorations
  • astronomical phenomena useful for navigation
  • Lake Geneva sailing boats
  • maritime scientific history

Are the contents free to access?

Yes. The documents published on Navigare Necesse Est are freely accessible in order to share maritime knowledge that can sometimes be difficult to find elsewhere.

Who is the author of the publications?

The content has mainly been written by P.-A. Reymond throughout his career in the merchant navy, recreational navigation, teaching and maritime research.

Does the site cover maritime law?

Yes. A significant part of the publications deals with the law of the sea, international conventions, territorial waters, Exclusive Economic Zones (EEZs), maritime regulations and international safety rules such as RIPAM / COLREG.

Can I learn astronomical navigation on this site?

Yes. The site offers numerous educational resources on astronomical navigation, sextant use, sidereal time, navigation stars, ephemerides and traditional positioning methods at sea.

Are the contents suitable for beginners?

Yes. Some documents are highly technical, while many others were written with a strong educational and popularization approach to make complex maritime concepts easier to understand.

Does the site also cover maritime history?

Yes. Navigare Necesse Est gives an important place to maritime history, great explorations, nautical traditions, ancient instruments, historical units of measurement and stories related to the sea.

Can I find information about yachts and recreational boating?

Yes. Several sections are dedicated to yachts, shipbuilding, CE standards, boat stability, maritime safety and recreational navigation techniques.

Why preserve traditional navigation methods?

Traditional methods help better understand the foundations of modern navigation and retain significant historical, cultural and educational value, even in the era of GPS and digital technologies.

Are there publications about the Swiss merchant navy?

Yes. The site includes several documents dedicated to the Swiss merchant navy, its functioning and its history.

Are the publications available in several languages?

Yes. Most documents are available in French, while some are also translated into German, English, Italian or Spanish. Translation work is still ongoing.

Can the documents be used for teaching or research?

Yes, provided copyright and legal notices are respected. The content represents a valuable resource for maritime education, nautical history and scientific popularization.

Is the site regularly updated?

Yes. New publications and documents continue to be added, particularly on navigation, maritime history, astronomical phenomena and the evolution of maritime law.

What kinds of topics can be found in the latest publications?

Recent publications include topics such as:

  • international waters
  • the Strait of Hormuz
  • eclipses
  • ancient measurements
  • time units in ancient China
  • sidereal time
  • sundials
  • historical nautical instruments

Why is the site called “Navigare Necesse Est”?

The Latin expression “Navigare necesse est” means “To sail is necessary.” This historical phrase reflects the fundamental importance of navigation in human exchanges, exploration and the history of civilizations.

Is the site only about maritime techniques?

No. Navigare Necesse Est combines technical, historical, cultural and human approaches in order to transmit a broad understanding of the maritime world and the knowledge connected to the sea.


Should you not find the document that interests you in your own language, you can always read it in French, and also sometimes in another language.

Until now, not all pages have been translated into D, GB, E and I. If you wish to help us with this task, we welcome your contribution. Contact us.

Navigare Necessse Est brings together a wide collection of documents dedicated to maritime navigation, navigational astronomy, the law of the sea, nautical history, naval technology, maritime traditions and seafaring culture.

The website offers educational, technical, historical and cultural content intended for sailors, navigation enthusiasts, students and anyone interested in the maritime world.