Omega Caliber 1666: Seamaster Multifunction Versatility with Quartz Precision

The Omega Caliber 1666 is a quartz analog-digital multifunction movement introduced in the late 1990s, primarily featured in the Omega Seamaster Professional Multifunction Quartz models. Designed for those who value both the look of a traditional dive watch and the convenience of digital functions, the 1666 delivers a smart blend of practical features and sporty elegance.

While less known than the X-33’s Caliber 1665, the 1666 was developed for civilian and professional use rather than aerospace missions. It offered multiple digital tools—such as alarms, chronograph, and second time zone—while preserving the signature Seamaster design language.

Technical Specifications

• Type: Quartz analog-digital multifunction

• Functions:

  • Analog time (hours, minutes, seconds)

  • Digital display for:

    • Time (12/24-hour format)

    • Date and day

    • Second time zone (T2)

    • Alarm

    • Chronograph

    • Countdown timer

• Display: Analog hands + LCD at 6 o’clock

• Backlight: No (non-illuminated LCD)

• Battery: CR1620 lithium cell

• Battery Life: ~2 years

• Accuracy: ±15 seconds/month

• User Interface: Crown and pushers

• Sound Alert: Yes (alarm tone)

The movement was likely based on an ETA quartz multifunction platform, customized by Omega with proprietary programming and integrated into sportier cases tailored to the Seamaster identity.

Watches Featuring Caliber 1666

The 1666 powered the Omega Seamaster Professional Multifunction Quartz (ref. 2521.81 and others). These watches combined the case design of the Seamaster Diver 300M—complete with wave dial, rotating bezel, and helium escape valve—with the digital versatility of Omega’s multifunction quartz line.

Key visual features:

• Screw-down crown and pushers

• Rotating dive bezel (often aluminum insert)

• Lumed sword or skeleton hands

• Digital screen subtly integrated at 6 o’clock

• Titanium or stainless steel cases and bracelets

These models were especially popular among those who wanted a professional-looking dive watch with added day-to-day utility, including dual time zones and alarms for travel.

Reliability and Maintenance

The Caliber 1666 is considered highly reliable, requiring only:

• Battery changes every 2 years

• Occasional servicing of seals and buttons (due to water resistance features)

The movement is generally stable, but some aging units may show LCD fading or loss of contrast. While replacement modules are limited, Omega service centers may still maintain or swap in compatible movements from donor units.

Collector Appeal

Though not as famous as the X-33 or mechanical Seamaster chronometers, 1666-powered watches are gaining popularity for:

• Functional versatility

• Classic Seamaster aesthetic

• Under-the-radar collectibility

• Better affordability than mechanical models

Clean, full-original examples—especially those with intact LCDs and original boxes—are increasingly appreciated among tool watch collectors and quartz enthusiasts.

Final Thoughts

The Omega Caliber 1666 is a smart, functional, and stylish quartz movement that gave the iconic Seamaster design a digital boost. Perfect for travelers, active professionals, and collectors of hybrid technology, it represents a unique and well-executed chapter in Omega’s multifunction legacy.