tag:blogger.com,1999:blog-6017098610385638884.post6784577232702603552..comments2024-03-08T08:37:35.800-08:00Comments on An Ocean Lover in Maine: Safety at Sea SeminarOcean Lover Mainehttp://www.blogger.com/profile/07026946733686967154noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-6017098610385638884.post-44321154757174331692016-03-20T23:41:37.604-07:002016-03-20T23:41:37.604-07:00> Demonstrating the best way to use a signal mi...> Demonstrating the best way to use a signal mirror. <br /><br />No - I've used that method and many others, at ranges of 10-22 miles, and I can assure you the depicted method isn't even a poor second.<br /><br />In fact the US Coast Guard will not approve a signal mirror that doesn't have a better aiming method than that depicted. They will only approve one that can be aimed by the double-sided mirror method (like the one in the photo) or one that has a retroreflective (aka "reflex" aimer). You can read the US Coast Guard requirements for approval of emergency signal mirrors at the USCG site online here:<br />http://www.uscg.mil/hq/cg5/cg5214/survivalequip.asp#160.020<br /><br /><br />> Make a target sight with your fingers then get the light between them.<br />> Ignore the directions on the mirror!<br /><br />Please don't do that - the life you save may be your own. <br /><br />Despite that comforting light on your fingers, the beam at range is a tiny fraction of the area between your fingers - reflect the light on a shaded wall 50-100 ft away to see that - it will look like this photo: https://flic.kr/p/dQgCVq<br /><br />The US Coast Guard, Royal Air Force, and National Bureau of Standards put a lot of work into finding effective ways to aim signal mirrors, including live tests in both the US and Britain with hastily trained novices then put in rubber rafts and rated at signaling to passing planes. They found that signal mirrors with retroreflective (aka reflex) sights worked by far the best, and double-sided mirrors next best (almost half as effective). You can read the US test report summary at these two pages:<br />http://babel.hathitrust.org/cgi/pt?id=mdp.39015010566720;view=1up;seq=135<br />http://babel.hathitrust.org/cgi/pt?id=mdp.39015010566720;view=1up;seq=154<br />The foresight aiming method mentioned there is a more sophisticated version of the finger method, using a far more accurate machined aiming wand. It came in 3rd, and is accepted for lifeboat use by many countries other than the US.<br /><br />The mirror in your photo is intended to be used as a double-sided mirror. A good training diagram and instructions on using that type (from a 1985 US Air Force survival manual) is here: https://flic.kr/p/dQ1dK9 The WW2 instructions are here: https://flic.kr/p/xWYRWA The WW2 training film for the glass double-sided signal mirror (same principle) is on YouTube here: https://youtu.be/vmnRrCVBaP0<br /><br />Our Boy Scout peak-peak signal mirror event (usually at ranges of > 10 miles), used double-sided mirrors from 1980-2009, but now have mainly switched to retroreflective aimers. Those who have used both have commented on how much easier the retroreflective aimers are - that's the type of mirror the USCG crew and USAF are equipped with. <br /><br />There used to be USCG-approved retroreflective signal mirrors, but not popular with shipowners because they were more expensive than the one in your photo. The last manufacturer I know of that made USCG approved retroreflective aimer lifeboat signal mirrors went out of business a few years ago. <br /><br />There are many retroreflective aimer signal mirrors out there (in fact all US military issue signal mirrors are of that type) mainly 3"x5" and 2"x3". However, the USCG requires 17 square inches of reflective area for approval (see above) so they don't qualify for USCG approval. Nonetheless, the USCG issued 3"x5" glass signal mirrors with retroreflective aimers to their own members up until the 1980s or so, and issue 2"x3" plastic signal mirrors with retroreflective aimers to their crew now. A photo of a number of currently available retroreflective aimer signal mirrors (and one "lookalike") is here: https://flic.kr/p/nrN6sv<br /><br />We teach the Scouts to make their own retroreflective aimer and double-sided signal mirrors (the former not waterproof) here: http://www.bsaontarget.org/mirrorsFlashes of Sunlighthttps://www.blogger.com/profile/09882917991008565873noreply@blogger.com