Side-by-side at a glance. Click a watch above to open the full reference page.

	Patek Philippe 5726A-001	Patek Philippe 3700/1A
Model	Nautilus Annual Calendar 5726A	Nautilus (first generation)
Caliber	Patek Philippe Cal. 324 S QA LU 24H -- in-house automatic, 28,800bph, 45h PR; annual calendar (requires single correction per year, at March 1) + moonphase + 24h indicator; integrated in Nautilus sports case	Patek Cal. 28-255 C -- ultra-thin automatic with date, 19,800bph, 40h PR, 29j; 3.71mm thick; integrated winding; used in 3700 Nautilus
Case size	40.4mm	42mm
Lug-to-lug	51mm	48mm
Years produced	2011–present	1976–1990
Brand tier	top-luxury	top-luxury
Era	modern	vintage
Movement tier	Unclassified movement	Unclassified movement
Market median (excellent / full-set)	n/a	n/a
Typical range	n/a	n/a
Confidence	low	low
Categories	sport, integrated-bracelet	integrated-bracelet, sport
Editorial	n/a	yes
Typical price (2026)	n/a	$80,000 – $150,000
Collector note	n/a	landmark: The Genta-designed original Nautilus; the porthole case language it introduced is still in production fifty years later.

Patek Philippe Nautilus Annual Calendar 5726A vs Patek Philippe Nautilus (first generation)