# 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:** 20\ **Page:** 1
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [May 10, 2015, 4:04pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/1 "2015-05-10T16:04:23Z")
Let’s assume I’m the navigator on a ship. Or the duty quartermaster. Or maybe the captain, it depends on the size of the ship. Anyway… At regular intervals, I plot our position on the chart and enter it in the log. If any changes in the course are necessary, I give instructions to the helmsman and enter them into the log. Here comes my question… Now the helmsman has a compass right in front of him, so I’m going to give him the desired _magnetic_ heading. For the log or the chart, is there a default? If I just enter the new course as 143°, is it going to be assumed that it’s a True or a Magnetic heading if I don’t specify one or the other? Should I enter _143° (147° Mag)_ or something like that? ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [May 10, 2015, 4:30pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/2 "2015-05-10T16:30:43Z")
Not a navigator, but the GPS on my friends bass boat displays true heading on its screen. I can’t imagine any modern ship or boat can’t do the same. And in the movies they always say something like “come right to 140”. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [May 10, 2015, 4:41pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/3 "2015-05-10T16:41:45Z")
Also note that whatever direction the ship is pointing, it won’t actually be moving in that direction. Winds and currents will move it sideways so what matters is the correction rather than the actual heading. “come right to 140” might be from a previous heading of 130, so it is a 10 degree correction to allow for a wind from the right. ---
**Author:** ![bizerta](https://avatars.discourse-cdn.com/v4/letter/b/3be4f8/32.png) [@bizerta](https://boards.straightdope.com/u/bizerta)\ **Post date:** [May 10, 2015, 7:23pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/4 "2015-05-10T19:23:35Z")
> [@Ranger\_Jeff](#): > > Let’s assume I’m the navigator on a ship. Or the duty quartermaster. Or maybe the captain, it depends on the size of the ship. Anyway… > > At regular intervals, I plot our position on the chart and enter it in the log. If any changes in the course are necessary, I give instructions to the helmsman and enter them into the log. Here comes my question… > > Now the helmsman has a compass right in front of him, so I’m going to give him the desired _magnetic_ heading. For the log or the chart, is there a default? If I just enter the new course as 143°, is it going to be assumed that it’s a True or a Magnetic heading if I don’t specify one or the other? Should I enter _143° (147° Mag)_ or something like that? When navigating, there is no room for ambiguity. When in doubt, specify both true and magnetic. OTOH, the helmsman should already have a general standing order such as “All compass headings are true unless specified otherwise” ---
**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 10, 2015, 8:11pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/5 "2015-05-10T20:11:24Z")
Well, when I was on the helm, I would just try to hold the given course on the compass in front of me. Since that was magnetic, the course was too. I don’t know if that’s how everyone else does it. Mine was not a typical ship. We didn’t steer a particular heading by number; it would be something like “west-by-north, half west”, and once even “full and by”. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [May 10, 2015, 8:16pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/6 "2015-05-10T20:16:54Z")
> [@Ranger\_Jeff](#): > > Let’s assume I’m the navigator on a ship. Or the duty quartermaster. Or maybe the captain, it depends on the size of the ship. Anyway… > > At regular intervals, I plot our position on the chart and enter it in the log. If any changes in the course are necessary, I give instructions to the helmsman and enter them into the log. Here comes my question… > > Now the helmsman has a compass right in front of him, so I’m going to give him the desired _magnetic_ heading. For the log or the chart, is there a default? If I just enter the new course as 143°, is it going to be assumed that it’s a True or a Magnetic heading if I don’t specify one or the other? Should I enter _143° (147° Mag)_ or something like that? From BIL who is in the business. > [@](#): > > Gus, > > Most if not all ships (not boats) steer with a gyro compass calibrated to true north which is the orientation for all marine navigation charts. Few if any ships ever steer by magnetic compass. It is just unnecessary. > > ”Ranger’s” question infers that he has had some form of navigation training, perhaps by the Coast Guard auxiliary or Power Squadron, where they do teach magnetic course navigation. When all you have aboard your vessel is a magnetic compass, then that’s what you steer by. As a practical rule, boat navigation treats all courses as true, unless one is navigating on a precise course line. Then correcting true to magnetic is necessary. The proper way to label is “\_\_\_\_\_ T) on top and (\_\_\_\_M) under the course line. Omitting the (\_\_\_\_\_\_T) labeling would not be incorrect. > > Hope that answers the question. 😃 🆒 ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [May 10, 2015, 8:18pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/7 "2015-05-10T20:18:05Z")
> [@Robot\_Arm](#): > > Well, when I was on the helm, I would just try to hold the given course on the compass in front of me. Since that was magnetic, the course was too. > > I don’t know if that’s how everyone else does it. Mine was not a typical ship. We didn’t steer a particular heading by number; it would be something like “west-by-north, half west”, and once even “full and by”. You were on the “Bounty” ??? :eek: ---
**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 10, 2015, 9:02pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/8 "2015-05-10T21:02:42Z")
> [@GusNSpot](#): > > You were on the “Bounty” ??? :eek: Not quite. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [May 10, 2015, 10:57pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/9 "2015-05-10T22:57:40Z")
He was on the Beagle! ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [May 10, 2015, 11:16pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/10 "2015-05-10T23:16:17Z")
> [@Robot\_Arm](#): > > Well, when I was on the helm, I would just try to hold the given course on the compass in front of me. Since that was magnetic, the course was too. > > I don’t know if that’s how everyone else does it. Mine was not a typical ship. We didn’t steer a particular heading by number; it would be something like “west-by-north, half west”, and once even “full and by”. > [@GusNSpot](#): > > You were on the “Bounty” ??? :eek: > [@GaryM](#): > > He was on the Beagle! In the early 1970s, a shipmate of mine was studying for his AB ticket and he was learning how to box the compass. I have no idea whether that is still required. ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [May 10, 2015, 11:36pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/11 "2015-05-10T23:36:58Z")
> [@tomndebb](#): > > In the early 1970s, a shipmate of mine was studying for his AB ticket and he was learning how to box the compass. I have no idea whether that is still required. Just to fight Ignorance - what is an AB ticket and what is “boxing a compass”? Some kind of Faraday cage? Just curious. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [May 11, 2015, 12:05am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/12 "2015-05-11T00:05:45Z")
Boxing the compass is naming all the headings around the compass. North North by east North North east East by North east Etc. There are 32 points to recite in clockwise and counter clockwise. > **[Box the Compass](http://seatalk.blogspot.com/2005/11/box-compass.html?m=1)** > > Back in the old days of sailing, when a new crewman was brought on board he had to begin learning the hundreds of ropes and sails and tools ... ---
**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 11, 2015, 12:13am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/13 "2015-05-11T00:13:36Z")
> [@GaryM](#): > > He was on the Beagle! 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). ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [May 11, 2015, 12:14am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/14 "2015-05-11T00:14:07Z")
Ab ticket: Able Bodied Seaman identification, issued, (in the U.S.) by the Coast Guard after working aboard a ship for a minimum period and passing several tests that indicate that one is actually an asset to the ship and not mere labor. I was an Ordinary Seaman, but since I was going back to college at the end of each summer, I did not pursue an AB ticket. (I don’t think I had accumulated the minimum number of months to apply for one at the end of my second summer, anyway.) [Boxing the compass](http://en.wikipedia.org/wiki/Points_of_the_compass): In the days before everyone went to a 360° compass, the compass card, (the face on which one reads directions), was noted by simply putting a mark half-way between North and East–Northeast, East and South–Southeast, etc. Then marking halfway between North and Northeast and between Northeast and East, etc., then continuing to set marks halfway between those marks, etc. At the end, there were 32 Points on the compass, (since, without trisecting an angle, one is not going to get to the 360 degrees). Boxing the compass was the method of identifying each point on the compass: North, North by east, North-northeast, Northeast by north, Northeast, Northeast by east, East-northeast, East by north, East, East by south, East-southeast, Southeast by east, Southeast, Southeast by south, South-southeast, South by east, South, South by west, South-southwest, Southwest by south, Southwest, Southwest by west, West-southwest, West by south, West, West by north, West-northwest, Northwest by west, Northwest, Northwest by north, North-northwest, North by west. Of course, 32 points, (at 11 1/4 degrees per point) still leaves a lot of play in setting direction, so one can further indicate direction by noting a half or a quarter point away from the point on the compass card (or compass rose). Thus, one can indicate “North-Northwest a half North” to indicate the direction halfway between North-Northwest and North by West. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [May 11, 2015, 12:38am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/15 "2015-05-11T00:38:42Z")
> [@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). I, for one, am impressed. Beautiful ship. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [May 11, 2015, 4:32am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/16 "2015-05-11T04:32:06Z")
> [@GaryM](#): > > I, for one, am impressed. Beautiful ship. ↑ ↑ ↑ This… ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [May 11, 2015, 4:32am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/17 "2015-05-11T04:32:21Z")
**GusNSpot** , your BIL answered my question and then a bit more. Thank him for me. You might want to relay to him my only experience at a was helm 2 minutes at a combination binnacle/helm/trainer they had at the Alameda TRACEN they had for Recruit training. There was just a wheel, rudder angle indicator, and compass card. And a box for the instructor to make the compass card go crazy and the recruit had to spin the wheel in the right direction. I think everyone ended up “chasing the card”, or was it “chasing the compass”? I was primarily a LORAN technician or instructor. During my tour at a LORAN station, one day I asked the skipper about the charting of a LORAN position and he showed me how you’d mark the position and time and label the position “LORFIX”. I guess now they use “GPSFIX” on both the charts and logs. What do they use for a celestial fix? Leave it blank by default? ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [May 11, 2015, 4:37am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/18 "2015-05-11T04:37:57Z")
Sent your question on. Included you in the email. I will post answer here also if you don’t do it first. ---
**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 11, 2015, 5:11am UTC](https://boards.straightdope.com/t/any-navigators-here/719707/19 "2015-05-11T05:11:31Z")
> [@GaryM](#): > > I, for one, am impressed. Beautiful ship. > [@GusNSpot](#): > > ↑ ↑ ↑ This… Thanks, both. It was very traditional; cotton canvas sails, sextants,[sup]\*[/sup] a cast iron stove,[sup]+[/sup] steering by the stars, and raising the anchor by hand. Helm instructions were done by the compass points that **tomndebb** described, so it’s not a completely lost art. - They had modern GPS and radios, but knew how to do celestial navigation, too. I read about one of their voyages where they did the Africa to South America leg with traditional navigation only. - I hear they’ve replaced the stove with a modern one, but I hope they kept the old one in their warehouse. It was too cool a thing to get rid of. ---
**Author:** ![Phu\_Cat](https://avatars.discourse-cdn.com/v4/letter/p/77aa72/32.png) [@Phu\_Cat](https://boards.straightdope.com/u/Phu_Cat)\ **Post date:** [May 12, 2015, 11:04pm UTC](https://boards.straightdope.com/t/any-navigators-here/719707/20 "2015-05-12T23:04:23Z")
Tomndebb, Thanks for the explanation about the AB ticket, MOST INTERESTING. Phu Cat [Next page](https://boards.straightdope.com/t/any-navigators-here/719707.md?page=2)