Navigation Weekend
June 4-6, 2010
Treworgy Planetarium at Mystic Seaport

For inquiries or to make a reservation, please use our contact form:
(Note: please do not attempt to send direct email to addresses at --use the contact form).
UPDATE: Schedule of events now available (see below)! This is still in flux, and we do still have room for presentations if anyone has a last-minute proposal. This has been updated again as of Sunday, May 23.

For reference, visit the web pages for the previous two Navigation Weekends:

The Treworgy Planetarium at Mystic Seaport in conjunction with the "NavList" online community is pleased to announce the third biennial "Navigation Weekend" devoted to preserving the art and practice of celestial navigation and nautical astronomy, to be held at Mystic Seaport in Mystic, Connecticut Friday and Saturday, June 4,5, 2010. This year, by popular demand, most of the principal presentations and activities are scheduled for Saturday (see below). No presentations are scheduled for Sunday, June 6, though we have left it open as a rain date for sextant sights.

In an era where most navigation at sea is done by GPS and other electronic means, a vibrant community of historians and enthusiasts preserve the art of using the Sun and Moon and the stars and planets to navigate across the globe. Celestial navigation enthusiasts and practitioners as well as professional and private historians of science will be meeting to discuss the history and future of celestial navigation. Many participants in the "Navigation Weekend" are members of the "NavList" online discussion group which is committed to traditional methods of navigation and position-finding (information page for NavList:

The "Navigation Weekend" will include special presentations and demonstrations by invited speakers on historical navigation methods including the "method of lunars" or "lunar distances" which was once the epitome of the navigator's art. Aspects of sextant use and adjustment will also be discussed, and there will be opportunities to take sights from nearby coastal locations using historic navigational instruments. This year we will also be focusing on aerial celestial navigation including a presentation by Gary Lapook on the celestial navigation issues during the fated final flight of Amelia Earhart in 1937.

The fee for attendance for the entire Navigation Weekend is $10 for Mystic Seaport Members and those who have paid full admission to the museum; $35 for those who are not members or have not paid admission. Presenters and members of the press are exempt from the attendance fee. Please email Frank Reed at to confirm your attendance. Also note, we are still open for presentations for the Navigation Weekend. Please contact Frank Reed if you would like us to consider your topic for presentation.


FRIDAY June 4, 2010:

Meet the Navigators
Planetarium Classroom (lower level, west side). Get your name badge, pay your attendance fee (if any), and meet your fellow navigation enthusiasts as well as Treworgy Planetarium staff, including R.M. "Max" Maxwell, Planetarium Manager.

Tour of the Collections Research Center
We'll get a behind-the-scenes look at the research center at Mystic Seaport, the museum within the museum, and if time permits, we will see some of the interesting navigational instruments in the collection. Mystic Seaport has required an additional fee for this tour of $10 per person.

A Textbook History of Bowditch's Navigator
Planetarium Classroom. A simple, bibliographic history of the "American Practical Navigator" by Nathaniel Bowditch from its beginnings as a revision of Moore's "New Practical Navigator" through the important editions published in his lifetime (through 1837) and on into the 19th and early 20th centuries when the publication was purchased by the US Government. Those attending will receive a DVD containing dozens of historical editions of Bowditch's Navigator (most of these are available on Google Books, but "local copies" are always nice to have).

A Special Event
In front of the Noank Historical Society museum, 17 Sylvan Street, Noank, CT. The navigators of NavList will be presenting a commemorative sign to the Noank Historical Society marking a little bit of history that connects this year's Navigation Weekend to the local history of Southeastern Connecticut. On February 7, 1931, legendary aviation pioneer Amelia Earhart was married to George P. Putnam in a private ceremony in the village of Noank (two miles south of Mystic Seaport). Gary Lapook, who will be doing a presentation on Saturday afternoon about the celestial navigation on Earhart's last fated flight, will be doing the "ribbon-cutting" at this event. Some refreshments will be served. This event is open to all, and we would love to have a crowd. We are expecting local news media join us.

Dinner in Noank
Friday's group dinner will be at “The Seahorse” in Noank, on West Cove. Please note that there will be no special activities during this dinner, but this will be an excellent opportunity to chat about navigation informally. Please expect to pay for your meal and drinks. Spouses and other guests are welcome.


Shooting Lunars and Jupiter in Daylight
Eastern Point in Groton, about five miles from Mystic Seaport. Hands-on experience shooting lunars (weather permitting). Also a challenge to shoot Jupiter in daylight. We will meet by the benches in the small park at Eastern Point here: Latitude=41.3193° N, Longitude=72.0748° W.


Meet the Navigators
Planetarium Classroom (lower level, west side). For those who did not attend Friday's sessions, get your name badge, pay your attendance fee (if any), and meet your fellow navigation enthusiasts as well as Treworgy Planetarium staff, including R.M. "Max" Maxwell, Planetarium Manager.

Scandals among the Lunarians!
Planetarium Classroom. Was Nathaniel Bowditch a thief? Did he "mutilate" the work of another nautical astronomer? Did the world steal from Elford? What was up with the Baron de Zach? The early 19th century saw the art of navigation turned into science, and while it happened, clever men, and a few women, too, tried to make a living from mathematics. They fought for customers and occasionally attacked each other in words that would make the Internet blush. Frank Reed will present a broad discussion of navigation by "lunars" or "lunar distances" and the math that made it all work in the context of these scandals and intrigues.

The Bygrave Slide Rule and Sight Reduction
Planetarium Classroom. Gary Lapook will discuss the amazing Bygrave cylindrical slide rule and demonstrate his modern "Flat Bygrave" adaptation. The Bygrave rule was standard equipment aboard British aircraft and airships in the early days of aerial celestial navigation. It was a marvel of design which could clear a standard celestial sight faster than almost any other non-electronic means of clearing sights. We will all learn how to clear common altitude sights using this extraordinarily efficient method.

Channel Islands Navigation Tools
A presentation of some tools developed by Greg Rudzinksi for coastal and celestial navigation. Everyone will receive one of Greg's nicely-constructed "kamals" or one of his Polaris "Latitude Wheeler" cards. Greg will not be physically present for this presentation and will instead join us virtually from California by webcam or at least web audio.

Shooting Lunars, Round Two
North end of Mystic Seaport grounds. More hands-on experience shooting lunars (weather permitting). Brad Morris will also demonstrate his historic "reflecting circle" which he will talk about in detail later in the afternoon. Also a challenge to shoot Jupiter in daylight. Conditions are not as favorable at this time of day, near noon, so if you're interested in trying this with your own hands, please try to make it to the early morning session at Eastern Point (see 7:30am above).


Celestial Navigation on the Complex Plane
Planetarium Classroom. Robin Stuart will show how the use of complex numbers transforms the spherical trigonometry used in celestial navigation into plane trigonometry and makes calculations conceptually simpler and more compact. His paper on this topic was recently published in NAVIGATION: Journal of the Institute of Navigation. Detailed derivations will be avoided with the primary focus being on the application of the resulting simple formulas to classical problems in celestial navigation. Specific examples taken from 19th and early 20th century texts will be treated. Prior exposure to the basic arithmetic of complex numbers would be helpful.

A Prismatic Circle
Planetarium Classroom. Brad Morris will demonstrate his historic reflecting circle, an exotic and unusual 19th century navigational and astronomical instrument. The story of how he acquired this instrument is as interesting as the instrument itself and involves negotiations over its apperance in a cable tv program.

Lunars and Altitude Accuracy
A presentation by Frank Reed on the altitudes used in clearing lunar observations. This will include a derivation of the required accuracy limits and the remarkable "miracle" that applies to lunars measured around 90 degrees. Also, the amazingly easy method for clearing lunars requiring almost no trigonometry that follows from this fact and was completely over-looked in the period when lunars were practiced at sea.

The Celestial Navigation Aboard Earhart's Electra
Planetarium Classroom. Gary Lapook, a noted expert in the subject of aerial celestial navigation as practiced in the early and mid 20th century, will present an analysis detailing the issues of celestial navigation on the fated circumnavigation flight of Amelia Earhart and navigator Fred Noonan in 1937. In particular, Gary will discuss the observations that might have been possible approaching Howland Island, on the last leg of the voyage, when Earhart and Noonan's Lockheed Electra disappeared without a trace.

US Navy Navigation
Planetarium Classroom. CDR Mike Nielsen, USN (ret) will discuss his experiences in navigation, celestial and otherwise, during his decades of service in the US Navy.

Dinner in Mystic
Moorings Restaurant at the Hilton Mystic. A buffet group dinner. Please expect to pay a flat $30.00 for dinner, not including drinks. Please plan on staying for the after-dinner presentation. Everyone who attends the dinner will receive at least two free navigation books donated by David Burch of the Starpath School of Navigation and Ken Gebhart of Celestaire.

A Commercial Report on Celestial Navigation
After dinner, Hilton Mystic. Ken Gebhart will talk briefly about Celestaire and developments in the world of sextant sales.
The Navigation of H.M.S. Bounty
After dinner, Hilton Mystic. Frank Reed will give a brief account of the celestial navigation, including many lunars, aboard the infamous Bounty commanded by William Bligh from late 1787 until the mutiny in April 1789. Bligh was highly skilled in the methods of scientific navigation which were becoming prominent at this time.

SUNDAY June 6, 2010

No Events Planned.
As of now, we have been able to fit all of the formal presentations into one long day on Saturday with a few less formal events on Friday. Please note that we may add presentations for Sunday afternoon if there is sufficient interest. Also if we need a "rain day" for sight-taking, and if there is sufficient interest, there will be more chances to shoot lunars on Sunday.

Mystic Seaport is located in southeastern Connecticut. You'll note that it's very close to Interstate-95, the major east coast highway. I-95 west of New Haven (which is about an hour west of Mystic) can be a driving nightmare, so I'll start with options to the east. Boston, Mass. is about an hour and half away by car. It's an easy drive, also an easy train trip (about two hours, see, and of course it's a wonderful travel destination all by itself. Many international flights fly into Boston's Logan airport. About 40 minutes away by car is T.F. Green airport south of Providence, Rhode Island. This is an extremely convenient airport, relatively uncrowded with numerous inexpensive flights. Southwest flies here. We recommend renting a car, but if you prefer not to, we can arrange rides.

There are also sometimes inexpensive flights into Bradley, the airport north of Hartford, Connecticut. This is about an hour and a quarter from Mystic. This is an international airport.

If you decide you want to visit New York City or you simply prefer flying into New York, LaGuardia airport, JFK, and Newark have many flights. The driving from New York is tough, to say the least. It's possible to take the train direct from Manhattan to Mystic or New London (about three hours, see From the small train station in Mystic, it's an easy half-mile walk to the museum.

Mystic itself is a great place to visit. If you haven't been to this area before, you may want to spend an extra day or two. In addition to Mystic Seaport Museum, the first nuclear submarine, Nautilus, is the center of the Submarine Museum a few miles away (only a small section of the submarine is open to visitors so that alone is maybe less interesting than it sounds). There are two enormous casinos about ten miles away with interesting entertainment options, some very good restaurants, and of course gambling, if that's your thing. And in general, Mystic, Noank, and Stonington are genuinely quaint New England seaside villages.

For lodgings, there are many unremarkable but pleasant motels near the highway about half a mile north of Mystic Seaport, a couple of nice B&Bs and smaller hotels closer to the center of town about half a mile south of Mystic Seaport, and if you rent a car, plenty of other choices within ten miles. The casinos have big, fancy hotels. When we held this event two years ago, there seemed to be a "center of gravity" of folks staying near the highway.

Legal disclaimer: Mystic Seaport, Frank Reed, and other participants in the Navigation Weekend cannot guarantee any of the events, activities, or participants in the Celestial Navigation Weekend. All events and activities are subject to change at any time. Participants are responsible for their own travel, food, accomodations, and other expenses. All other activities at Mystic Seaport require museum admission or membership.

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