I sestanti prodotti dalla Davis sono tra i pių apprezzati sestanti di plastica in produzione. In particolare il modello Mk15 ha prestazioni che si avvicinano notevolmente ai pių costosi modelli in metallo. Costruito dalla californiana Davis Instruments č costituito da una struttura in materia plastica resistente al salino ed agli urti con  un'ottica molto  curata ed un nonio a tamburo di notevole precisione.

• Large, easily adjusted mirrors using new instrument-quality glass and a special baked on salt-spray resistant backing. Both mirrors have protective housings.

• Horizon mirror is half-silvered. No adjustment wrenches required.

• Molded of high-impact, weather-resistant plastic. All Davis Master Sextants feature the following professional specifications: 7" (178 mm) frame radius. Graduation 120° to -5°

• Index mirror rectangular, 1.98" x 1.49" (50 x 38 mm).

• Precision machined slow travel gear and worm mechanism.

• Highly visible, easy-to-read micrometer drum and vernier allowing readings to 2/10 minute of arc.

• Fully ribbed, three-circle sextant body for platform strength and stability.

• Large, contoured handle designed for sure, steady grip and angled back for added control.

• Seven large sunshades allow complete, independent adjustment of shading density for horizon and index mirrors.

• 3 x 27 mm star telescope with anti-reflective coated glass lenses, plus separate hooded sight tube for glare-free sun shots.

• Neck lanyard frees hand and protects sextant.

• Tough, fully padded, shock-resisting carrying case with compartments for extra mirror kits.