Housing a perpetual calendar inside the Nautilus case, this replica Nautilus 57401G blue is among the most mechanically ambitious references in the entire collection. The 5740/1G-001 packs day, date, month, leap year, and moon phase indicators into a 40mm white gold case without adding significant thickness. That engineering restraint defines the 5740: all the complexity of a grand complication compressed into a sport-watch format. The blue dial maintains the horizontal embossing pattern while integrating multiple subdials and apertures for the calendar displays. Few watches attempt this level of complication density at 40mm.

Build Details

• Case diameter: 40mm
• Case material: white gold
• Dial: blue with horizontal embossed texture and perpetual calendar displays
• Crystal: sapphire
• Bracelet: integrated white gold
• Movement: automatic ultra-thin perpetual calendar
• Functions: hours, minutes, perpetual calendar (day, date, month, leap year), moon phase

The perpetual calendar tracks 30-day and 31-day months automatically and requires no manual correction until the year 2100. The moon phase indicator displays lunar cycles with high precision, adding an astronomical function to an already complex dial.

What Collectors Notice

Perpetual calendars in sport-watch cases are rare across the industry. Most manufacturers house this complication in dress-watch formats where case thickness is less of a constraint. Patek Philippe achieved the thin profile by using the 240 Q caliber family in the genuine version, one of the slimmest perpetual calendar movements ever produced. The blue dial on white gold creates the same visual pairing found in the classic 5711 family, connecting this grand complication back to the Nautilus core identity. For a simpler calendar function, the 57261A annual calendar offers day-date-month tracking in steel. Both sit in the Nautilus collection, bridging sport design and horological depth.

This vs Other Versions

The 5740 stands at the top of the Nautilus complication hierarchy. Annual calendars like the 5726 track months but need a manual correction each March. The perpetual calendar inside the 5740 eliminates that step entirely. White gold construction signals its position above the steel references, and the blue dial keeps it visually linked to the Nautilus heritage. This replica Nautilus 57401G blue is the pinnacle of what the Nautilus platform can accommodate mechanically.