UTC Time & Date
Sextant Sight (Sun)
°
'
DR Position
°
'
°
'
Sight Reduction
1. Altitude Corrections
| Sextant Altitude (Hs) | -- |
| Index Error (IE) | -- |
| Apparent Alt (Ha) | -- |
| Dip (HE) | -- |
| Refraction | -- |
| Semi-Diameter | +16.0' |
| Observed Alt (Ho) | -- |
Instructor's Note: We are converting the reading on your instrument into a "True" altitude observed from the center of the Earth.
- Index Error: This is a mechanical calibration of your sextant. Always apply it first to get your 'Apparent' altitude.
- Dip: This corrects for the height of your eye above the water. A higher position makes the horizon appear lower, needing more correction.
- Refraction: Light bends as it enters the atmosphere, making the sun look higher than it really is. We must subtract this effect.
2. Astronomical Data
| Sun GHA | -- |
| Sun Declination | -- |
| Assumed Lon | -- |
| Local Hour Angle (LHA) | -- |
3. Intercept & Azimuth
| Computed (Hc) | -- |
| Observed (Ho) | -- |
|
INTERCEPT
--
AZIMUTH (Zn)
--
|
|
Instructor's Note: The Intercept is the distance between your DR position and your actual Position Line (LOP).
If your result is "Toward" (T), draw your LOP closer to the sun's azimuth. If "Away" (A), draw it further away.
Check these first
Running Fix Walkthrough
Step 1: Plot your first LOP based on the intercept and azimuth.
Step 2: Advance the first LOP along the ship's course. Distance = Speed × Time between sights.
Step 3: Plot your second LOP from the new DR. Where it crosses the advanced line is your Running Fix.
This intersection gives you a "Most Probable Position" when a simultaneous fix isn't possible.