NauticTools2All NauticTools2 tools
27 calculators for coastal navigation, celestial navigation and tides – each with its full working, so every problem can be followed step by step on paper. Built for training, exam preparation and passage planning.
Coastal navigation 12 tools
Course Conversion
Convert a course from compass course to course over ground and back, with deviation, variation, leeway and current.
Bearing Conversion
Convert a bearing from relative bearing via compass and magnetic bearing to true bearing.
Current Triangle
Course and speed over ground, the course to steer, or the current that is setting you.
In detail: current triangle ›Dead Reckoning
Mid-latitude or Mercator sailing: destination from course and distance, or course and distance between two positions.
Great Circle Navigation
Great circle route with initial and final course, vertex, meridian crossings and the saving over the rhumb line.
Limiting Course
Possible course sector of a vessel from its visible navigation lights and your bearing to it – your own position can be moved with a slider.
In detail: limiting course ›Geographical Range of Lights
Distance to a light that is just rising above or dipping below the horizon, from height of eye and height of the light.
Distance by Vertical Angle
Distance to an object of known height from its sextant angle, with the base visible or hidden below the horizon.
Distance, Speed and Time
The basic rule of navigation: the third value from any two.
Magnetic Declination
Variation for any position and date, back to 1900.
Rail Log
Measure speed without a log: a float and a stopwatch along the length of the boat.
Time Systems
UTC, zone time, local time and the other times used on board, from one moment and the longitude.
Celestial navigation 10 tools
Fix from 2 or 3 Altitudes
Intercept method with position lines, cocked hat, running fix and the offset from the DR position – from sextant altitudes or directly from Ho, Hc and Az.
In detail: fix from altitudes ›Sextant Altitude Corrections
From sextant altitude Hs to observed altitude Ho: index error, dip, refraction, semi-diameter and parallax.
Computed Altitude and Azimuth
Hc and Az from DR position, declination and local hour angle – the working step behind every position line.
Ephemeris Calculation
Declination and Greenwich hour angle of the sun, moon, planets and 83 stars for any moment.
Latitude by Meridian Altitude
Latitude from the sun's altitude at its meridian passage.
Sun-Run-Noon Fix
Morning position line plus noon latitude: the classic fix from two sun sights.
Index Error
Determine the index error of your sextant.
Meridian Diagram
Zenith, celestial pole, equator and body in the classic construction.
Rising and Setting Times
Rising and setting of the sun, moon and planets, with civil, nautical and astronomical twilight.
Star Chart
The sky for any place and time with constellations and navigational stars – for finding your stars at twilight.
Tides 5 tools
Tides ATT
Admiralty Tide Tables with a tidal prediction form laid out like the exam form, seasonal changes and crossing a bar. ATT 2005 exam data included.
In detail: tides with the ATT ›Tides BSH
Height of tide at a time, or the time for a minimum depth, by the method of the German BSH tide tables with the real mean spring and neap curves.
My Sailing Area (BSH)
The same calculation with high and low waters taken automatically from an imported station.
Age of Tide
Springs, mean or neaps for any chosen date.
Moon Phases
New moon, first quarter, full moon and last quarter of the current lunation.
Not for navigation: NauticTools2 is meant for training, exam preparation and passage planning. For navigation on board, use the official publications.
NauticTools2 is free and runs on Windows 10 and 11. An Android version is in preparation.
Get it from the Microsoft Store