Sailing - Navigation

General information about navigation

Overview / Ueberblick

There are several types of navigation. As they all have advantages and disadvantages it will depend on the location, tools available, type of boat, experience of the sailor and conditions, which one is the most appropriate. There are traditional types of navigation (celestial navigation, piloting, dead reckoning), which are mainly based on observations of celestial bodies (stars, sun) and/or fixed geographic objects and the use of charts and trigonometric methods. In addition you will find modern forms (satellite navigation, radar and radio based navigation), which are based on the use of electronic instruments. The overview already highlights the main differences of traditional and modern techniques. The former rely on the regular determination of the position by visual contact to an object or celestial body, but without the need of functioning electronic instruments. The latter, however, will rely exactly on those instruments, but without the need of regular sight to objects or celestial bodies, i.e. also at night or in dense weather.

  1. BulletOverview about the different types of navigation ( (german)

  2. BulletInteractive Navigation Course (by Diederik Willemsen) - basic and more advanced information about projections, longitude and latitude, maps incl. chart symbols, magnetic variation and deviation etc. (english) overview (english)

  3. BulletVery comprehensive and academic collection of information about navigation and all related topics (german). One of the best resources we have seen !!! Therefore you will find some more links to Rainers page below. The overview deals with different projection systems, positioning etc. / Koordinatensysteme, Standortbestimmung etc.

  4. BulletESYS - overview about navigation (terrestrial and celestial navigation, tools and instruments) (german)

  5. - by Andreas Siemoneit (german)

  6. BulletOverview about navigation at wikipedia (english) (german)

  7. BulletBasic equipment for navigation / Basisausstattung fuer die Navigation (by Bobby Schenk) (german)

Traditional Navigation

Celestial Navigation / Astro Navigation
Back in the old days there were no GPS tools to assist you in finding your way around. Nevertheless, in the middle of the last millennium Spanish galleons made their way to America, which proves that navigation over long distances was possible. The invention of ‘precise’ working clocks and information about the position of sun and stars facilitated navigation at that time.

Celestial navigation is based on the observation of celestial bodies (stars, sun, moon) and the measurement of their position or the distances between each other with a sextant. With the help of nautical almanacs, tables or manual trigonometric calculation (or in modern times with computers) the sailor can transform the measurements into lines on a nautical chart and determine its position.

  1. BulletAn introduction at wikipedia (english) (german)

  2. BulletAstrosail - tutorial about celestial navigation, sextant, ‘time definitions’ / Astronavigation, Sextanten, Definition der Zeit, Hoehenbeschickung etc. (german)

  3. BulletESYS on celestial navigation (german)

  4. BulletIntroduction into celestial navigation / Einfuehrung in die Astronavigation by Peter Kosch (german)

  5. BulletKowoma’s guide to different projections, longitude and latitude etc. (german) and on celestial navigation (german)

  6. BulletRainer Stumpe has set up a very interesting page with lots of information about celestial navigation,
    incl. information about the measurement of time and how to determine the geographic direction (

Pilotage and dead reckoning / Karten- oder terrestrische Navigation / Kompasspeilung

With the method of ‘dead reckoning’ the navigator will project the future position of a boat by firstly, carefully noting its current position as a starting point on a nautical map. Secondly, he will draw certain lines from this starting point towards its proposed destination, which symbolize the steered course and distance made by the boat in a given time (speed).  The resulting position is most likely not the true position, which the boat will reach after having travelled the exact course at the assumed speed. Currents, leeward movements caused by wind and incorrect steering will influence its real position. Navigators can reduce the margin of error between the originally determined ‘dead reckoning’ position and the ‘real’ or ‘estimated position’ by accounting for such effects. The set (direction) and drift (speed) of currents can be estimated based on ‘current maps’  and the leeway can be assessed based on the force of the wind and the type of the boat.

Piloting (or Pilotage) means the regular fixing of the boats position with reference to geographic or hydrographic elements. Different methods can be used to obtain the position. There are electronic chart systems, which will assist the navigator almost automatically and manual methods, which will include the manual use of plotters, compasses, maps and calculators. An element common to all forms is the frequent fixing of the position. It can be obtained by two or more bearings to fixed geographic elements or floating navigation aids noted in the map (although bearings to the latter usually lack the necessary accuracy). Another method is a fixing by range (obtained by radar, sextant, sonar etc.), whereby intersecting range arcs determine the position. Combination of different methods are also common.

Learn more about piloting, finding your position and the navigation with a map

  1. BulletAstrosail - Introduction to piloting / Einfuehrung in die terrestrische Navigation (u.a. Standlinien (inkl. optische Peilung,  Feuer in der Kimm, Hoehen- und Horizontalwinkel, Funk- und Radarpeilung), Doppelwinkelmessung, Besteckaufgaben, Stromaufgaben) (german)

  2. BulletVery detailed guide to plotting and piloting (by Rainer Stumpe) incl. dead reckoning (Koppeln, Besteckversetzung, Stromversetzung etc.) (german)

  3. BulletChapter 4 of Diederik Willemsen’s interactive course - Plotting & Piloting (english)

  4. BulletESYS - terrestrial navigation (german) incl. Kreuzpeilung, Versegelungspeilung etc.

  5. BulletPilotage / Terrestrische Navigation - wikipedia (english) (german)

  6. BulletDead Reckoning / Koppelnavigation - wikipedia (english) (german)

Modern Navigation

GPS- or satellite Navigation

The satellite navigation or GPS (global positioning system) is based on 24 satellites placed in several orbits of the Earth. The signal of at least four satellites should be accessible for the user anywhere on the Earth. To determine a position of a user the system will measure the time a signal travels from the satellite to the receiver and calculate the respective distance. By combining at least four measurements one can determine the position of the user quite precisely.

  1. BulletGPS at wikipedia (english) (german)

  2. BulletComprehensive information about the GPS system, satellites, Galileo ( (german)

  3. BulletArticle about the pros and cons of GPS instruments - abrief buying guide by Bobby Schenk (german)

  4. BulletBasics about the GPS system (by Toralf Schumann) (german)

Radar Navigation

Radar systems measure also the time a signal travels between the transmitter and the receiver. Compared to GPS, whereby the satellite functions as the transmitter and the receiver is based on the Earth, a radar system combines transmitter and receiver and measures the total (return) time a signal needs to travel between the radar and a certain object, which reflects the signal. Provided the object gives a proper reflection, the system allows a quite accurate determination of the distance to the object. Radar can also be used to provide a (approximate) bearing of the object.

  1. BulletAstrosail - tutorial by Frank Sauer (german)

  2. BulletArticle by Bobby Schenk about the use of a radar (german) and a link to download a comprehensive 144 page booklet from Dieter Lunge, former head of the radar and echolot section of Atlas Werke AG (pdf)

  3. BulletThe history of radar - pdf presentation (english)

  4. BulletInfo about radars systems on ESYS with small pdf booklet and radar plotting sheet template (german)

  5. BulletThe principle of a radar navigation - national geospatial intelligence agency (english pdf)

  6. BulletRadar - wikipedia (english) (german)

Radio transmission / Funkverkehr auf See

Once commonly used, ‘radio direction finders’ are nowadays mainly used in emergency cases only as the worldwide coverage has been reduced and the range of the signals is quite short. The signal from a transmitter at a known location can be used for a bearing and thus used for piloting.

In general radio transmission is used for communication these days. If you sail on your local lake, it is not necessary to know how to operate a radio transmitter. However, if you plan to sail on a busy river or out on the sea or use a motor boat on a canal with commercial ships it is advisable to learn how to use it.

To operate a radio transmitter on a boat you need to have a license. to ensure that you are familiar how to operate these systems and which rules need to be observed.

  1. BulletComprehensive information about the radio transmission and certain regulation/systems like SOLAS, GMDSS, SAR and DSC (german, but partly also in english) german-english translation of radio terms including english phrases (pdf)

Charts, navigation aids, tools & instruments

Nautical Charts / Seekarten
Nautical charts are mainly based on the so called ‘Mercator projection’, a certain type of cylindrical projection, which has proved to be the most useful way to create a nautical map. There are normal, paper charts or modern electronic charts. Charts will include information on shorelines, depth of water, other topographic information, lighthouses, significant geographic objects, dangerous points (like rocks or wracks) etc. and are usually issued by the national cartographic or maritime bodies for certain regional areas.

  1. BulletChapter 2 of Diederik Willemsen’s interactive course - charts incl. chart symbols etc. (english)

  2. BulletNorwegian chart service - very good for swedish and norwegian coast (please check correctness of maps and terms on the page before using them ( tip: choose ‘sjokart’ and zoom of at least ‘6’ (norwegian)

  3. - project to promote open nautical maps (english) (german)

  4. BulletNorwegian maps - by Kystverket (Norwegian Coastal Administration) (norwegian / english)

  5. BulletUS & global nautical maps - US Dept. of Commerce, Nautical Service (english)
    Free download of US Chart No. 1 (

  6. BulletWikipedia on nautical maps (english) (german)

  7. BulletLink page to several maps (Spain, Croatia, Greece, Calabrien, Malta & Gozo etc.) by ESYS (german)

Navigation Marks & Floating Lights / (beleuchtete) Seezeichen
Find detailed information about navigation marks and floating lights

  1. BulletAgain Rainer Stumpe provides lots of information concerning Seezeichen on his page, including codes for floating lights and light houses (german) (including animated floating light intervalls (oscillating etc.)  / mit animierten Leuchtfeuerkennungen)

  2. BulletChapter 9 of Diederik Willemsen’s interactive course - floating lights and marks (english)

Tides / Gezeitenkunde
Tides are movements of the water caused my gravitational attraction of the moon and the sun. The tide is the vertical movement of the water (rising and falling water) and the tidal currents are horizontal movements of water associated with the tide. Tidal currents are superimposed by ‘other’ currents caused by general oceanic movements and wind or other weather related water movements.

Learn more about the development of tides, different types, the influence of the moon and sun, the forces causing currents etc.

  1. BulletComprehensive, almost academic guide to the development of tides with lots of background information (by Rainer Stumpe) incl. tide tables, German-English-Terms etc. (german)

  2. BulletChapter 6 - 8 of Diederik Willemsen’s interactive course - Tidal Movements (english)

  3. (by Andreas Siemoneit) - basics about the tidal movements (german)

Tools and Instruments / Werkzeuge und Instrumente
Different instruments are used to assist the navigator to find the right way

  1. BulletAIS - Automatic Identification System - wikipedia (english) (german) ESYS (german)

  2. BulletChip Log (used for dead reckoning (speed measurement) / Logge fuer die Koppelnavigation - wikipedia (english) (german)  at ESYS (german) at (german) (pdf log template)

  3. BulletCompasses (magnetic compass, gyrocompass, electronic compass) (english) (german)

  4. BulletGPS (see above)

  5. BulletRadar (see above)

  6. BulletRadio transmission (see above)

  7. BulletSextant - tool to measure the angel between points/objects. It will be used to determine the altitude of celestial bodies or the distance to an object with a known height. (english) german)

  1. BulletGetting a licence & sailing courses

  2. BulletSeamanship / Seemanschaft

  3. BulletNavigation & maps

  4. BulletOrganisations & laws

  5. BulletTechnical information

  6. BulletOther links resources



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