Gnomonic Charts - Features and Uses

This video explains the essential and salient features of a gnomonic chart used for great circle sailing by mariners. The difference between a gnomonic and Mercator chart is also explained. The video also explains how courses are transferred from a gnomonic chart to a Mercator chart and why it is done so. Contents of this video will benefit mariners preparing for exams (written and oral examinations). Mariners will also benefit by watching the following videos: Information on paper charts: https://www.youtube.com/watch?v=L4L6wihfaIc&t=27s DR and fix position, effects of wind and current, set and drift: https://www.youtube.com/watch?v=y22P1YOntjk&t=7s Running Fix (Transferring position lines): https://www.youtube.com/watch?v=4sWeF0DFRKk&t=618s Tidal diamonds: https://youtu.be/8lYz3cyMvSg Finding the course to steer to counteract tidal currents: https://youtu.be/5DQyUv34zQw Basic terms, terminology, and symbols: https://youtu.be/ugvNDyM0IUg Allowing for the effect of wind and current on ship’s course and speed: https://youtu.be/A8T4i4nLIzA Counteracting for the effect of current and leeway to determine the course to steer: https://youtu.be/fSd8xJ1LXI8 The use of position lines - https://youtu.be/HlKFaIaaZWs Rising and dipping of lights: https://youtu.be/bxb9-IoG3PI Tides General Theory: https://youtu.be/f0e2hQUE8D4 Secondary port tide calculation: https://youtu.be/tv_oYTEccg0 Tidal window calculations: https://youtu.be/eq_4LHi1kvU Explaining the interpolation in secondary port tide calculation: https://youtu.be/y783OI-tjh0 Mercator charts and sailings: https://www.youtube.com/watch?v=La8KG4jrhPQ Great circle sailing and Gnomonic Charts: https://www.youtube.com/watch?v=aMjf5Bqt5Pg Passage plan with reference to tides and currents: https://youtu.be/4G-dQ6D1eeU Paper charts (essential features): https://youtu.be/s4YHShjn6qQ Corrective map of the world: https://youtu.be/yPvHZoxswVE