NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Emergency Navigation 2015
From: Lu Abel
Date: 2015 Jun 5, 21:40 +0000
From: Lu Abel
Date: 2015 Jun 5, 21:40 +0000
The newly released USCG smartphone app has several nice features. One of them indeed is a big red "help" button which promises to call the nearest Coast Guard center. Not only will it give them your latitude and longitude, but it will supply a description of your boat (presuming you've taken time to fill out the description section of the app).
The feature I like the most is the one that allows you to easily create a float plan (use pre-filled-out description of your boat [length, type, color, etc] along with a description of where you're going and when you should return) and directly email it to up to three different people.
Having been a boating safety instructor for a quarter of a century, I can tell you that failure to let someone on shore know where you're going and when you will be back is a giant hindrance when one runs into problems offshore. A couple of years ago four American football players went out for a Saturday of fishing in the Gulf of Mexico. They capsized their boat. Their absence was not noted until one of them failed to show up for work on the following Monday -- and then search and rescue had no idea where to look for them. Result was that by the time the boat was found only one of the four was still alive.
Several other good features in the app, too.
Don't know how it is finding it on Android, but at the iPhone store you have to search for "United States Coast Guard" [and not anything shorter] to find it.
From: Brad Morris <NoReply_Morris@fer3.com>
To: luabel@ymail.com
Sent: Friday, June 5, 2015 2:11 PM
Subject: [NavList] Emergency Navigation 2015
The US Coast Guard has released an app for your phone. The most important feature is calling them for help. It grabs your lat long and sends it to them.And there you have it. Its portable, its usually with you, and you can summon the USCG, under the assumption you are in cell tower rangeOn Jun 5, 2015 1:47 PM, "Bob Goethe" <NoReply_Goethe@fer3.com> wrote:There seem to have been several "aha" moments in the growing understanding of spherical geometry. For instance, there was an "aha" regarding the Sumner line in the first half of the 19th century, and the St. Hilaire method in the second half.At what point did people realize that the observed height of a celestial object equated, at the rate of 60 nm per degree, to the distance to the geographic point?I read Lecky's "Wrinkles..." and it seems that in the late 1800s, there were still sailors who were skeptical about great circle routes being the shortest distance between two points. Lecky had a section where he seemed to be engaging in a sort of "great-circle evangelism".Given that you can do a great circle calculation with Pub. 229 from where you are to any point on earth, treating your destination's latitude and longitude as though it were the "geographic point" of some celestial object, it would seem that there was some sort of leap that people needed to make in equating Hc with "miles remaining for us to sail in this trip".Was there in fact an "aha" moment here? Or was this obvious to people as soon as they worked out the basic mechanics of celestial navigation?I find that in talking to novice navigators today, the relation between height-of-celestial-object and distance-to-GP-in-nautical-miles seems to come as a bit of an eyebrow-raiser...it seems to produce an "aha" moment when it is first introduced to them.And though I can't remember exactly what I was thinking 35 years ago when I first got a sextant, I think that I also had a bit of an aha moment..with a sense that I would not have figured this out on my own if somebody else had not told me.Bob
