# Any navigators here? **URL:** \ **Category:** Factual Questions\ **Created:** [May 10, 2015, 4:04pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707 "2015-05-10T16:04:23Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [May 13, 2015, 1:59pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/21 "2015-05-13T13:59:56Z")
> [@Robot\_Arm](#): > > You’re getting closer, sort of. > > Rather than prolong the hijack, I’ll just say that I sailed on the [Picton Castle](http://en.wikipedia.org/wiki/Picton_Castle_%28ship%29). Nice little barky there Mr. Bonden. ---
**Author:** ![Spiny\_Norman](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@Spiny\_Norman](https://boards.straightdope.com/u/Spiny_Norman)\ **Post date:** [May 13, 2015, 7:49pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/22 "2015-05-13T19:49:33Z")
No Magellan I, but I did take a “classical” navigation class with the American Sailing Association, taught by a retired USN navigation officer. Before the advent of gyro compasses, when navigating a large craft, you would juggle 3 different figures: [ul] [li]True - the course you actually wanted to sail as drawn on the chart. (Compensated for leeway and drift, of course.)[/li][li]Magnetic - corrected for the local variation between true North and magnetic North. [/li][li]Compass. This course has been corrected both for variation and for the ship’s own influence on the compass (deviation).[/li][/ul] The helmsman will be looking at the compass, and so he’ll need the Compass course. The deviation varies depending on the ship’s orientation, but the navigator will have a table at hand. (For smaller craft, there’s not a lot of difference.) And so the navigator will plot his course, correct for variation and deviation, then give the helmsman a Compass course. In the USN, at least, if he needs to communicate his course (or a desired course for another craft), he will communicate in True. Most charts will have a compass rose in both True and Magnetic, to eliminate errors made in addition and subtraction, replacing them with errors committed by reading the wrong damn compass rose. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [May 13, 2015, 7:58pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/23 "2015-05-13T19:58:46Z")
> [@Spiny\_Norman](#): > > Before the advent of gyro compasses, when navigating a large craft, you would juggle 3 different figures: > > [ul] > [li]True - the course you actually wanted to sail as drawn on the chart. (Compensated for leeway and drift, of course.)[/li][li]Magnetic - corrected for the local variation between true North and magnetic North. [/li][li]Compass. This course has been corrected both for variation and for the ship’s own influence on the compass (deviation).[/li][/ul] My ship is posting updates on Facebook; location, course, etc. Their current course is “full and by”, which means “screw the compass, keep the sails full”. They’re on their way back to their home port for the first time in a couple years. That should be quite an arrival. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [May 13, 2015, 8:20pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/24 "2015-05-13T20:20:00Z")
> [@Spiny\_Norman](#): > > Most charts will have a compass rose in both True and Magnetic, to eliminate errors made in addition and subtraction, replacing them with errors committed by reading the wrong damn compass rose. East is least and West is best as far as I recall. ---
**Author:** ![Spiny\_Norman](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@Spiny\_Norman](https://boards.straightdope.com/u/Spiny_Norman)\ **Post date:** [May 13, 2015, 8:52pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/25 "2015-05-13T20:52:34Z")
> [@Robot\_Arm](#): > > My ship is posting updates on Facebook; location, course, etc. Their current course is “full and by”, which means “screw the compass, keep the sails full”. “Time spent sailing fast is rarely wasted” is a sound concept. 😃 ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [May 14, 2015, 2:46pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/26 "2015-05-14T14:46:12Z")
Nice thread. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [May 14, 2015, 2:57pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/27 "2015-05-14T14:57:13Z")
Hey I was a navigator! My experience was a little different. My first MOS was Aeroscout Observer. I was the left-seater in a scout helicopter. GPS units were just coming on the market. The most technologically advance equipment in the helicopter was me and my map. We did a mix of pilotage and dead reckoning and terrain association. It was a juggling act between dealing with grid headings on the map, magnetic headings on the instruments and accounting for wind deflection. Often at 100 knots NOE. Lots of fun. I miss it. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [May 14, 2015, 3:27pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/28 "2015-05-14T15:27:30Z")
> [@Loach](#): > > Hey I was a navigator! My experience was a little different. My first MOS was Aeroscout Observer. I was the left-seater in a scout helicopter. GPS units were just coming on the market. The most technologically advance equipment in the helicopter was me and my map. We did a mix of pilotage and dead reckoning and terrain association. It was a juggling act between dealing with grid headings on the map, magnetic headings on the instruments and accounting for wind deflection. Often at 100 knots NOE. Lots of fun. I miss it. I assume that’s where your [username](http://en.wikipedia.org/wiki/Hughes_OH-6_Cayuse) comes from? ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [May 14, 2015, 3:34pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/29 "2015-05-14T15:34:12Z")
> [@UncleRojelio](#): > > I assume that’s where your [username](http://en.wikipedia.org/wiki/Hughes_OH-6_Cayuse) comes from? Yes it is. I had left active duty and joined the Guard where they were still using OH-6s instead of OH-58s around the time that I started needing screen names and email addresses. I have kept in ever since despite the fact that I haven’t worked with helicopters in a very long time. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [May 14, 2015, 4:26pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/30 "2015-05-14T16:26:46Z")
> [@Loach](#): > > Yes it is. I had left active duty and joined the Guard where they were still using OH-6s instead of OH-58s around the time that I started needing screen names and email addresses. I have kept in ever since despite the fact that I haven’t worked with helicopters in a very long time. Well, it’s a cool user name, much better than [LittleBird](http://en.wikipedia.org/wiki/MD_Helicopters_MH-6_Little_Bird). ---
**Author:** ![Whiskey\_Dickens](https://avatars.discourse-cdn.com/v4/letter/w/9fc348/32.png) [@Whiskey\_Dickens](https://boards.straightdope.com/u/Whiskey_Dickens)\ **Post date:** [May 14, 2015, 6:24pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/31 "2015-05-14T18:24:05Z")
> [@Robot\_Arm](#): > > You’re getting closer, sort of. > > Rather than prolong the hijack, I’ll just say that I sailed on the [Picton Castle](http://en.wikipedia.org/wiki/Picton_Castle_%28ship%29). Holy cruds! The ship that Laura Gainey was swept from. [Previous page](https://boards.straightdope.com/t/any-navigators-here/719707.md?page=1)