GLH130-40 Marine Nautical Sextant Navigation Instrument

GLH130-40 Marine Nautical Sextant with Case | Premium Navigational Instrument

The GLH130-40 Marine Nautical Sextant is the pinnacle of classical celestial navigation, built to satisfy the high standards of modern nautical regulations. This high-precision optical equipment is aimed at professional mariners, navigators and nautical enthusiasts and permits exact angle measurements between the horizon and celestial bodies (such as the sun, moon and stars) to establish a vessel’s geographic position.

Constructed from high grade corrosion resistant components, the GLH130-40 guarantees absolute reliability, even in the most extreme salt water conditions. Comes with a heavy-duty form-fitting protective storage container to protect the fragile optics and mirrors from vibration, shock and moisture in transit or rough seas. This sextant is an invaluable asset on any bridge, either as a primary navigation instrument or as a reliable, EMP-proof backup to modern GPS systems.

Technical Specifications

Part Number Cross-References

• GLH-130-40 (Standard)
• NS-130-40-MAR (Alternative Military/Commercial Spec)
• SKU: 8944-GLH130

Compatibility

• Fully compliant with standard commercial vessel bridges, naval fleets, training academies, and private yachts.
• Integrates seamlessly with standard nautical almanacs, sight reduction tables (e.g., Pub No. 229/249), and traditional plotting tools.

Applications

1. Primary & Backup Blue-Water Navigation: The fail-safe, non-electronic locating system for transoceanic expeditions.
2. Commercial Merchant Vessel Compliance Complies with SOLAS regulations for providing backup navigational equipment for commercial vessels.
3. Maritime Academy & Naval Training: A key instrument for teaching cadet officers the foundations of celestial navigation and line-of-sight location.
4. Emergency Disaster Preparedness: Delivers absolute operating capabilities in the event of total electronic failure, cyber-attack or GPS satellite outages.

Expert Calibration Guide

When you first unbox your GLH130-40, your primary objective is checking for Perpendicularity, Side Error, and Index Error.

1. Set the index arm precisely to 0°00.0
2. Look through the telescope at a sharp, distant horizon line.
3. If the reflected horizon and the direct horizon do not form a perfectly unbroken straight line, you have Index Error.

Guide from our Marine Engineer:

1. The “On the Arc / Off the Arc” Rule: Always calculate your Index Error before a sight session. If the error is “on the arc” (greater than zero), subtract it from your reading. If it is “off the arc” (less than zero), add it. Remembering the old mariner’s rhyme will save you from major plotting blunders: “If it’s on the arc, it’s off; if it’s off the arc, it’s on!”
2. Maintenance is King: Salt spray is the natural enemy of precision optics. After every watch, gently wipe down the frame with a microfiber cloth dampened with fresh, distilled water—never use harsh chemical solvents on the mirrors. Ensure the micrometer screw is lightly coated with high-grade, acid-free instrument oil.
3. Storage Tip: Never store the sextant in its case with the index arm loose. Clamp it securely at a mid-range position to distribute tension evenly across the rack teeth.