Using a sextant to get accurate angle measurements is tough on moving vessel. It's even harder when the waters are rough. Is there a technique that is most useful in stabilizing the device and/or the body holding it to keep the sextant focused on its target?
Here is what I have found for taking sights in rough seas.
- Get a feel for how the vessel is rolling so that sights can be timed to when the vessel is at its most stable which will most often be at the top of a wave.
- Heaving-to can reduce the motion.
- Take multiple good sightings and average the results.
- Knowing which sightings are good comes with practice.