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Re: Lost at Sea with a sextant puzzle
From: Brad Morris
Date: 2019 Jun 23, 15:27 -0400

Just thought of one more use for the sextant.

Remove the index mirror and use it as a signaling mirror to SAR aircraft. Scratch an × into the silvering on the mirror so it can be properly pointed at the aircraft. This won't directly "quench your thirst" but will indirectly, when SAR hands you a bottle of water.

On Sun, Jun 23, 2019, 3:18 PM Greg Rudzinski <NoReply_Rudzinski@navlist.net> wrote:

Doug,
If the raft navigator has only a sextant then Polaris in the northern hemisphere could be observed for a rough (+/- 40') latitude. To get longitude requires an accurate watch set to UTC. Timed equal altitude sights of the Sun can then generate an accurate longitude. Getting an accurate latitude from a noon sun observation requires knowledge of declination of the sun at the moment of local apparent noon (LAN). The one page pub 249 Sun LTA would be handy to have for sun declination determination (a good add to the sextant box). If star declinations are available then an accurate latitude can be reduced from a star observation at meridian passage. Hopefully emergency food, water, pilot chart, strobe light,flares, and VHF/Aircraft hand held radio are aboard the raft. If not then the only value of knowing where you are while drifting would be for rationing food and water until the raft drifts down wind down current to a lee shore.
Greg Rudzinski

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