Home > Public Domain Data > Be a Wise Consumer of Fun Posts, too!

Be a Wise Consumer of Fun Posts, too!

Around this time of year, versions of the following story seem to make their way around the internet:

The passenger steamer SS Warrimoo was quietly knifing its way through the waters of the mid-Pacific on its way from Vancouver to Australia. The navigator had just finished working out a star fix & brought the master, Captain John Phillips, the result. The Warrimoo’s position was LAT 0º 31′ N and LON 179 30′  W.  The date was 31 December 1899.

“Know what this means?” First Mate Payton broke in, “We’re only a few miles from the intersection of the Equator and the International Date Line”.  Captain Phillips was prankish enough to take full advantage of the opportunity for achieving the navigational freak of a lifetime.  He called his navigators to the bridge to check & double check the ships position.  He changed course slightly so as to bear directly on his mark.  Then he adjusted the engine speed. The calm weather & clear night worked in his favor. 

At midnight the SS Warrimoo lay on the Equator at exactly the point where it crossed the International Date Line! The consequences of this bizarre position were many:  The forward part (bow) of the ship was in the Southern Hemisphere & the middle of summer. The rear (stern) was in the Northern Hemisphere & in the middle of winter.  The date in the aft part of the ship was 31 December 1899.  Forward it was 1 January 1900.  This ship was therefore not only in two different days, two different months, two different years, two different seasons, but in two different centuries – all at the same time.

I have successfully used many types of geographic puzzles with students and with the general public over the years, and I enjoy this story a great deal.  But in keeping with our reminders on this blog and in our book to “be critical of the data,” reflections on the incorrect or absent aspects to this story can be instructive as well as heighten interest. The SS Warrimoo was indeed an actual ship that was built by Swan & Hunter Ltd in Newcastle Upon Tyne, UK, in 1892, and was sunk after a collision with a French destroyer during World War I in 1918.  Whether it was sailing in the Pacific in 1899, I do not know.

The version of this story on CruisersForum states that it is “mostly true.”  What lends itself to scrutiny?  Let us investigate a few of the geographic aspects in the story.

First, the statement, “working out a star fix” leaves out the fact that chronometers were used to work out the longitude, rather than a sextant.  (And I highly recommend reading the book Longitude by Dava Sobel).  Second, the International Date Line (IDL) as we know it today was not in place back in 1899.  The nautical date line, not the same as the IDL, is a de jure construction determined by international agreement. It is the result of the 1917 Anglo-French Conference on Time-keeping at Sea, which recommended that all ships, both military and civilian, adopt hourly standard time zones on the high seas. The United States adopted its recommendation for U.S. military and merchant marine ships in 1920 (Wikipedia).

Third, the distance from LAT 0º 31′ N and LON 179 30′ W to LAT 0º 0′ N and LON 180′ W is about 42 nautical miles, and the ship could have traveled at a speed of no more than 20 knots (23 mph).  Therefore, conceivably, the ship could have reached the 0/180 point in a few hours, but whether it could have maneuvered in such a way to get the bow and stern in different hemispheres is unlikely, given the accuracy of measurement devices at the time.  Sextants have an error of as at least 2 kilometers in latitude, and chronographs about 30 kilometers in longitude. Or, they could already have reached the desired point earlier in the day and not have known it.  Even 120 years later, in my own work with GPS receivers at intersections of full degrees of latitude and longitude, it is difficult to get “exactly” on the desired point:  Look carefully at the GPS receiver in my video at 35 North Latitude 81 West Longitude as an example.  An interesting geographic fact is that, going straight East or West on the Equator along a straight line, it is possible to cross the dateline three times (see map below).

Our modern digital world is full of fragments that are interesting if not completely accurate, but as GIS professionals and educators, I think it is worth applying “be critical of the data” principles even to this type of information.  The story is still interesting as a hypothetical “what could have happened” and provides great teachable moments even if the actual event never occurred.


The International Date Line (CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=147175).

  1. josephkerski
    January 2, 2017 at 5:05 pm

    One of my colleagues sent me this article about Mark Twain’s musings about time zones and the Equator, here: https://quadriv.wordpress.com/2011/10/02/mark-twain-and-the-s-s-warrimoo/ I love it.

    • January 2, 2017 at 11:52 pm

      The Mark Twain link shows that it was conventional before 1900 to adjust the date when crossing the 180th Meridian. The book “Following the Equator” (http://www.biblioteca.org.ar/libros/167735.pdf) was copyrighted in 1897 and Twain calls the meridian “the Great Meridian” rather than the International Date Line.

      It seems to me reasonable that, if he was really that close, the captain of the Warrimoo may have decided to place his vessel as close as possible to the equator and the great meridian at the dawn of the new century.

      The 20th century didn’t truly begin until 1/1/1901, rather than 1/1/1900. But people probably didn’t believe that any more in 1900 than they did in 2000 that it wasn’t a new millennium yet.

      • josephkerski
        January 3, 2017 at 4:00 am

        Great points – thanks for reading and replying! Hope all is well in Montana.

        –Joseph Kerski

  2. January 7, 2017 at 3:03 pm

    Love the map @ bottom, of which I took a humouristic twist as a concludign slide to young pros http://www.slideshare.net/azolnai/oil-price-and-innovation/12

    • josephkerski
      January 7, 2017 at 8:21 pm

      Andrew – thanks for this – I love the strong man graphic in the Pacific – that will help me to remember the route that the date line follows from now on!

      I also looked at your other slides – quite a story you have! I had forgotten about your Esri past service too! You should write this up in a book or something so people will understand your history but also an encouragement for students and those in the workforce to “keep reinventing yourself and be a lifelong learner” which you so well model!
      –Joseph Kerski

  3. July 28, 2017 at 8:55 pm

    The issue of accuracy is certainly relevant in this story, but your account here has a few issues. You say that the mention of a star fix ” leaves out the fact that chronometers were used to work out the longitude, rather than a sextant.” Not really. A chronometer gave Greenwich time, but a navigator needed local time to compare against it. The difference in time, Greenwich minus local, yielded the longitude at the standard rate of 15 degrees per hour (or 1 degree for every four minutes of time and so on… it’s just proportioning out 360 degrees in 24 hours). So how do you get local time? Until the middle of the 20th century, this was done by turning a sextant into an accurate sundial: measuring the altitude of the sun or a star would yield local time (after a few simple corrections for things like refraction, and in the case of the Sun, the equation of time). Later you say that the accuracy of this was only “about 30 km in longitude”. I suspect you’re thinking of the very first timepieces that could be counted as chronometers, like Harrison’s. By 1899/1900 the time kept by a typical chronometer was a few seconds after some weeks at sea, and many vessels carried three (or more!) chronometers. The error in the sextant sight for local time also added an error of a few seconds. The net implied an uncertainty comparable to or or perhaps double the uncertainty in latitude: a few miles for each. Needless to say, the vessel could not have been positioned with anything like the accuracy implied in the story. It’s a tall tale.

    Frank Reed
    Clockwork Mapping / ReedNavigation.com
    Conanicut Island USA

    • josephkerski
      July 29, 2017 at 4:08 am

      Thanks Frank for the clarification!
      I looked at your ReedNavigation site… very important work you are doing and I salute you.
      You might like my new book:

      In it I wrote several chapters on instrumentation, surveying, mapping, exploration, and so on.

      –Joseph Kerski

  4. Phil Ciglen
    October 30, 2018 at 11:32 pm

    Another problem with this story is that the 20th century began on Jan 1, 1901, since there was no year “0”; the first year would be year “1”, and so forth.

    • josephkerski
      October 31, 2018 at 11:00 pm

      Good point, Phil! Just like a few years back on 1 Jan 2000, all those articles saying, we’re really not in the 21st Century quite yet….

  5. Adam Q
    October 31, 2018 at 9:21 pm

    A friend of mine researched the sailing schedules of the Warrimoo and found that she was indeed in the area at the end of December in both 1899 and again a year later in 1900. So it was indeed possible. However, as you point out,the navigators, with the technology available at that date, could not possibly have measured their position to the accuracy required.

    • josephkerski
      October 31, 2018 at 11:00 pm

      Thanks Adam Q. Indeed. It could have very well happened, but even if not, it is fun to think about and is instructive for teaching purposes too, about lat-long, navigation and positional technologies, history, etc….

  6. Gina Dunn
    December 23, 2018 at 2:35 pm

    According to the National Ocean service (https://oceanservice.noaa.gov/facts/international-date-line.html) the international date line was established in 1884, giving credence to the story, but have to agree with the discussion that it would be impossible at that time to determine its exact position. However, as you point out, fun to think about nonetheless….

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