Nautical Calculation Companion
by Alastair Buchan

Nautical Calculation Companion

Every essential calculation you need for coastal and offshore navigation This book is an aide memoire bringing together in an easy to understand guide all the frequently needed but often forgotten equations and formulae needed by sailors.

The format is the same throughout: the equation followed by a worked example to show how it should be done. Line drawing illustrations help the reader understand what they are doing and why they are doing it.

Calculations included are:

Distance to the visual horizon and the radar horizon
Distance off by vertical sextant angle, horizontal sextant angle, bearings and echo ranging
Calculating course made good, course to steer, set and drift of current and speed and direction of true wind
Sailing to weather and Storm avoidance
Calculating speed through water for estimate time on passage, distance sailed, maximum hull speed for a displacement vessel and spacing of knots on log line
Calculating amplitudes and azimuths of sun and stars.
Calculating wave height, wave length, wave period
Measuring degrees converting degrees, minute and seconds to degrees and decimals of degree
Measuring length Converting imperial units to metric and metric to imperial
Measuring mass Converting imperial units to metric and metric to imperial
Measuring speed Converting imperial units to metric and metric to imperial
Measuring Volume Converting imperial units to metric and metric to imperial. This also includes US measures.

Contents:

Introduction
Conventions
Amplitudes for Compass Checks
Distance to the horizon
Distances Off
Speed, Time, Distance
Current Sailing
Sailing to Weather
Storm Avoidance
Wind
Plane Sailing
Magnetic Variation
Waves and Swell
Draft when Heeled
Rule of Twelfths
Conversion Factors