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Solar Eclipse in NW Europe - 20 March 2015 - 02 March 2015

There will be a solar eclipse on 20th March, visible from the UK and many other parts of North West Europe. Unfortunately here in the UK we won't be able to see a full eclipse, but we will see the moon pass in front of the sun. Follow the link for more information.

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US Army rediscovers celestial navigation - 20 October 2014

After GPS totally displaced most other forms of navigation, there is a growing awareness that GPS (and other systems like GLONASS, Galileo, Beidou etc) is very susceptible to jamming and other forms of interference. So the US army are turning the clock back, to include celestial navigation in their laser targetting systems.

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Hoegh guards against GPS failure with WinAstro - 15 May 2014

Hoegh Fleet Services, who manage a fleet of over 50 car carrier ships, have decided to guard against GPS failure on their vessels by getting a fleet wide licence for WinAstro. Unlike GPS and other GNSS systems, astro navigation cannot be jammed, spoofed, or suffer from systems or satellite failures! Whilst e-LORAN will provide a much needed alternative means of navigation for coastal waters, it will be a considerable time before it offers widespread coverage.

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Article on Yacht Navigation by Sextant - 15 May 2014

People may be interested in this blog article reviewing a book on navigating in the Victoria (BC) to Maui (Hawaii) using just a sextant for navigation (back in 1982, predating GPS). It also comes up with other useful comments on navigating by the stars.

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New Contact Details - 06 January 2014

With the European Space Agency having provided us with office space at Harwell for our


project, we have closed the old office at the Portsmouth Technopole - we can only fill one office! E-mails remain unchanged, but the phone number has changed to +44 (0)7985 927376.

23rd Greatest Breakthrough Since the Wheel - 06 January 2014

The Atlantic magazine has made a list of the 50 greatest breakthroughs since the wheel in its Octover 2013 issue. The sextant came in at number 23, with the sailboat at 40.

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Web Site - 16 December 2013

Apologies for the web site having been down the last few weeks. We had some server problems, and pressures of work meant we decided to fix things in a major server upgrade, without doing a short term fix. The upgrade was finished last week, and all is working well again.

Sextant navigation in Falklands War aircraft - 01 April 2012

Back in 1982 we English had a spat with the Argentinians over the Falklands (or Malvinas) Islands - it doesn't seem like 30 years ago.

One of the missions flown by the RAF was sending a Vulcan bomber 8,000 miles to bomb an Argentinian airfield - navigated by sextant.

Channel 4's film on this, Falkland's Most Daring Raid, can be viewed online. It is also reviewed by the Daily Mirror.

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New Dava Sobel book on Copernicus - 28 September 2011

There's a new book out on Copernicus, by Dava Sobel, who wrote the best seller Longitude. I haven't had a chance to read it yet, but if Longitude is anything to go by it'll probably be a good read, but lacking in depth for me. I preferred Umberto Eco's "The Island of the Day Before" to Longitude. Anyway, there's a review of her book in

The Economist



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Inexpensive training sextants - 06 May 2011

Many people want an inexpensive sextant for practicing ashore - either to learn astro navigation without making a large investment in a quality sextant, or to keep in practice when the boat's sextant is not around. We can now offer this with the AstroMedia sextant, which costs just £15.75, and is remarkably good quality and accurate for this price.

We will also be adding additional sextants to our product range in the near future, from Astra, Freiberger and others.

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GPS jamming in US by Lightsquared - 02 February 2011

Lightsquared, who are developing a US wireless data network, have been granted permission to use frequencies that are used by GPS, even though t is proven that thios will stop GPS receivers from operating near their transmitters. Luckily, sextants are not affected!


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WinAstro reviewed by Practical Boat Owner - 25 January 2011

Practical Boat Owner has reviewed WinAstro and given it a very good *** rating. You can read the review here on the web site. 

Mike Richey passed away - 25 January 2011

Mike Richey, expert on astro navigation and famous for his single-handed races across the Atlantic in the 26 foot junk rigged boat "Jester", passed away on 26th December at the age of 92. He was also one of the founders of the Royal Institute of Navigation, and served an apprenticeship with the sculptor and typrographer Eric Gill.
Read his obituary here.

WinAstro reviewed by Seil magazine - 30 July 2010

The Norwegian magazine Seil has reviewed WinAstro. The report, written by Terje Bølstad, is available for reading on Seil's web site - he has been an enthusiastic user of WinAstro for many years..

WinAstro now with Planetariom Software - 30 July 2010

WinAstro is now supplied with a separate planetarium program, Stellarium, that lets you see the sky at night from your location, and identify the stars, planets and constellations. This helps you identify the body you want to take a sight on, and more generally to identify all the objects in the sky - a great way to make those night watches more interesting!

You are here > Sextants > Freiberger
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Freiberger Sextants

Freiberger sextantsFreiberger are a long established German manufacturer of sextants and optical survey equipment, with all the well known attributes of German engineering. As well as supplying the sextants, they also have an excellent after sales service, offering spare parts, repairs and servicing, so you can be assured of a long life for your sextant.

Freiberger Drum Sextant

Freiberger Drum Sextant

This is a high quality full size aluminium sextant, manufactured to the highest standard to produce a high precision instrument. Accuracy of the instrument is ±20" of arc. It has a comfortable weight, is well balanced, and the wooden handle is comfortable. The clamping device and micrometer drum are fully enclosed for protection against dirt and sea spray.

The sextant has generously sized index and horizon mirrors, silvered on the front face for maximum accuracy. There are 4 shades for the index mirror, and 3 for the horizon mirror, to protect your eye when taking a sun sight. The sight scope is 4x40 with excellent optics, and a protective rubber eyepiece. The sextant comes in a wooden box, with an adjustment key, test certificate, and manuals for operation and adjustment.

Arm radius 170 mm Dimensions 26 x 24 x 13cm
Scale -5° to 125° Weight 1.4 kg
Micrometer vernier resolution 0.1' Box dimensions 34 x 32 x 17cm
Scope 4x40 Box weight 4.5 kg
Index mirror 57 x 42 mm
Horizon mirror 57 mm ø

 The sextant is available with either the traditional split horizon, or a full horizon.


Freiberger Yacht Sextant

Freiberger Yacht Sextant

This sextant is made tot he same high standards as the Drum sextant, but is smaller (7/8 size) and significantly lighter - the lightest metal sextant we know of on the market. This makes it ideal for those who find a lighter sextant easier to use, but who don't want the compromise in accuracy of using a plastic sextant. Although the smaller size sacrifices some accuracy, it is still accurate to ±40" of arc.

It has 3 index and 2 horizon mirror shades. The 2.5x magnification sight is ideal for keeping stars in view when the boat is bouncing around, as it has a wider field of view than higher magnifications. A nice touch is that the rubber eyepiece does not rotate when focussing the sextant, which many will find an advantage. The sextant uses the traditional split view horizon. The sextant comes in a wooden box, with an adjustment key, test certificate, and manuals for operation and adjustment.

Arm radius 142mm Dimensions  24x21x11 cm
Scale -3° to 123° Weight 0.86 kg
Micrometer gradation 1' Box dimensions  27x24x15 cm
Scope 2.4x25 Box weight 2.6 kg
Index mirror 57 x 29 mm
Horizon mirror 57 x 29 mm