16

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?

TomSchober
  • 413
  • 2
  • 9
  • 2
    Not enough for an answer, but the traditional technique is to use your body to stabilise the sextant - use your natural balance. – Rory Alsop May 27 '16 at 09:48
  • Yes, I figured there was some sort of body positioning involved, but I don't know a specific technique. – TomSchober May 27 '16 at 15:36
  • when the waters are that rough, you shouldn't care where you are: only care that you're not capsizing! – GrapheneDude May 27 '16 at 16:57
  • 1
    I agree your FIRST priority is safety. Yes, keep the vessel upright. However there are plenty of waters that are consistently rough, i.e. the mouth of the Hudson or Long Island Sound. These are great places to practice a running fix with a sextant, but hard because of the waves. – TomSchober May 27 '16 at 17:01
  • 2
    Graphene - while that is a useful point, it doesn't answer the question, and quite often you have to know your position despite the rough waters. – Rory Alsop May 27 '16 at 20:20
  • Practice, practice, practice. Experience is the only way to become reasonably accurate in all conditions. That experience will also tell you what your margin of error is likely to be in various sea states/types of vessel. The actual technique you use will depend a lot on you and the vessel you are in, but there is no substitute for experience here. – vascowhite Jun 10 '16 at 09:10
  • 1
    Yes @vascowhite that's what I'm trying to gleen from the other nautical-types here. ;) So in your experience, objectively analyze how you hold the sextant in a rough situation. – TomSchober Jun 10 '16 at 14:30
  • 1
    Heaving-to might help. – A E Jun 14 '16 at 15:53
  • I assume you're supposing the sun is going to be out while the waters are rough? In my experience, it's typically clouded over when Poseidon is cranky. – ShemSeger Jul 12 '16 at 04:46

1 Answers1

7

Here is what I have found for taking sights in rough seas.

  • Practice
  • 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.

The information I found was from Reed's Sextant Simplified by Dag Pike on pages 29,42,and 50

Charlie Brumbaugh
  • 69,253
  • 35
  • 217
  • 423