Carte en temps réel des navires - AIS - trafic maritime et positions. Vous présente : Marine navigation courses: Running fixes and sextant angles: 5 piloting. Skip over navigation Doubled angle fix The Doubled angle on the bow fix resembles a running fix though only one navigation aid is used. In the example on the right the initial angle (30°) on the bow is doubled (60°) yielding an isosceles triangle . The distance travelled between the bearings is the same as the distance from the visible wreck. Start with the visible wreck having a bearing of less than 45° off the bow (α), note the log distance. Proceed along the course until the angle on the bow is doubled (β), read the log: d1 is 10 nm.
Four point fix If the first angle on the bow is 45°, a special situation occurs: The Four point fix, so called since 45 degrees equals 4 points on the compass (1 point = 11,25° ). Special angle fix The Special angle fix requires the mariner to know some special pairs of angles (a : b) that give the distance travelled between bearings as equal to the distance abeam . Remember: the greater the angular spread the better. Mathematics: isosceles triangle fixes . Special angle fix. Ship Construction. Maritime.