- Astro Navigation Theory
- Use of UKHO’s NavPac 4 Calculation Software
- Programmable Calculator Methods
- Practical use of the Marine Sextant
Satellite technology enables almost every mariner to use electronic navaids to fix their position on the oceans. however, electronic systems can be disrupted by errors in a satellite or its ground control systems, defects in shipboard equipment or interference with satellite signals. the celestial chart therefore remains the most reliable tool for mariners navigating out of sight of land.