Ranks 5 Stars
The overall condition of this prestige sextant is excellent.
It is just waiting to go back to sea and where it can be put back to use. It also is perfect for a serious student or
a professional who is seeking something special
I’ve been involved selling Tamaya sextants for over 30 years, and my company Nautech Maritime Corporation was instrumental in the design and introduction of their MS 733 SPICA, MS 833 Jupiter, and MS 933 Venus sextants and the famous NC 2, and NC 77 navigation computers.
Therefore, it brings me pleasure to present a used 1983 Tamaya Jupiter sextant, Serial Number 65885, with both a 4 x 40 star scope, 7 x 35 sun scope made by the factory.
The two scopes today cost about $550.00, and a base sextant sells for around $1300.00 street price. Expect new sextant prices to rise in 2008, and to pay $2000.00 for a new Tamaya MS 833 Jupiter with two scopes.
The case is the new style plastic one which is much improved feature over the early wood case.
USING SEXTANT TELESCOPES:
4 x 40 is considered a STAR Scope because it transmits more light through the optics than higher powered scopes. Its wider field of vision is an advantage in low light conditions.
7 x 35 and 7 x 50 are considered SUN scopes because their higher power adds greater
definition to the horizon and the sun’s limbs. It really makes for a precise LAN sight. On bright nights, they work well with the moon. and can capture early rising planets at twi-light.
As power increases, the ability to keep a steady image decreases. Anything over 7 x 50, unless stabilized, has too narrow a field of vision, and the image moves too much to be of
much use from small craft.
When given in the specs, Relative Brightness, Relative Light Efficiency
(adds
50% for coated lens to RB), and Twilight factor are helpful in
comparing the amount of light that reaches the eye between
various scopes.
For terrestrial objects, all you need is a sighting tube, magnification is unnecessary because you need to be fairly close in to shore to make out the objects and identify them.
CONDITION: Irrespective of age, overall condition, is excellent. The lighting works. All moving parts turn freely. Nothing is broken. The only exceptions are some scratches on the case and one missing cap (shade) for the scopes’ ocular lens which is a small thing. They are rarely, if ever, used. There is a small spot on the inside of the 7 x 35 scope’s objective lens. Mirrors are perpendicular to frame. Both mirrors are without blemish. The sextant’s paint on the frame is as new. All the numbers match. This sextant is excellent condition. Adjustable index and side error are nil.
STAR RATING: Without qualification, this instrument rates 5 STARS
QUALIFICATIONS: We are one of the few company’s still selling navigation instruments that know anything about them. For purposes of judging whether Joel’s opinion counts, he was the editor of the chapter on sextants of the 1977 Edition of “Bowditch”, The American Practical Navigator, NAVPUB 9; a member of the U.S. Naval Academy Navigation Symposium Board, 1975 -1978; the author of a book on marine sextants, Cornell Maritime Press,1975,
and the founding president of Nautech Maritime Corporation which partnered with Tamaya of Japan in the introduction of the MS 733 Spica, the MS 833, Jupiter, MS 933 Venus sextants and the famous NC-2 navigation computer, in the U.S. market. Joel is a retired Master Mariner, and held a U.S. Navy “D” Qualification as a Senior Skipper – Oceans. For six years he was a Varsity Offshore Coach at the U.S. Naval Academy.
Some of his memberships include the: Association of Naval Aviation, Silver Wings,
The Tailhook Association, Naval Academy Sailing Squadron, McCampbell’s Aces Squadron, Naval Historical Foundation, and the Naval Order of the United States.
Model 833
JUPITER STANDARD SPECIFICATIONS:
Measuring Range: -5 to 125 degrees
Accuracy:
+/-12 seconds.
Telescopes: 4x40mm: angle of view 7 degrees, relative brightness 100. All optics are fully
coated.
Frame: Lightweight die cast aluminum alloy with corrosion resistant black finish. Bronze arc.
Vernier
Scale: has 5 marks & reads to 0.2′.
Index Mirror: 57 x 42 mm. aluminized on the rear side.
Horizon
Mirror: 57mm diameter.
Shaded:
1. 4 for index mirror
2. 3 for horizon mirror
Weight: 3 lbs 12
oz, 7 lbs in case
Carrying case: Plastic
INCLUDED ARE:
1 Tamaya Nautech Model 833 sextant frame
1 4 x 40 Star scope
1 7 x 35 Sun scope
1 Split image horizon mirror
1 bulb installed
1 Mirror adjustment wrench
1 New style plastic sextant case
1 Tamaya Certificate of Accuracy
Batteries not included. They should be inserted with the positive terminal to the top.
For those seeking more information about the modern marine sextant I suggest
they get a copy of a book written in 1975, now out-of-print. The Myths & the Truth about Selecting a Marine Sextant. Cambridge MD: Cornell Maritime Press, 1975. 44pp, 10 illustrations.
Topics include scope power, mirrors, shade glasses, theoretical brightness, accuracy, workmanship, accuracy, comparison of
specifications. It is available at the University Library, all locations, of The California State University for
free.
