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Mark 25 Sextant


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Model # 137216 | Mfg # 25

Many experienced navigators prefer the plastic-framed Mark 25 to metal sextants for some very good reasons, and affordability is only one of them. The instrument’s light weight makes it easier to hold steady for accurate reading. Replaces the conventional half-silvered mirror with a full-field dielectric beam converger and combines horizon and celestial images in a single field for easy, reliable sights even in low light conditions. LED illumination floods the arc and drum with soft light for night use.

  • Frame Material: Reinforced plastic, upgraded for stability
  • Sighting System: Full-field beam converger
  • Scope Magnification: 3 x 27mm
  • Filter Shields: Seven large sunshades
  • Arc Range: 120° to -5° of arc
  • Drum Calibration: 2/10 minute of arc
  • Lighting: LED Illumination
  • Weight: 16.5oz.
  • Case: Padded shock-resisting case
  • Included Accessories: Well-written instructions and case
  • Warranty: One year

Mark 25 Sextant

Material Plastic
Type Sextants
Warranty Details One Year

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by PowerReviews
Davis Instruments Mark 25 Sextant

(based on 1 review)

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Reviewed by 1 customer

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(8 of 8 customers found this review helpful)


Excellent intro tool for celestial navig

By HD Zone

from Lake Oswego OR


  • Good value for cost


    Best Uses

    • Learning Celestial

    Comments about Davis Instruments Mark 25 Sextant:

    Very easy to use and to keep in adjustment. The lighter color than the Mark 15 proved to be less affected by being out in the sun and temperature changes. More than adequately accurate for learning purposes, and performed at least as well as the all-metal units in our class in accuracy and reproducability. User needs to remember that this is a precision instrument, not just plastic junk, and so needs to be cared for like the big-dollar metal units. If properly used and maintained it will give years of accurate use and service. I have had mine for several years now and it still works great.

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