Omega Seamaster 300M, Modern vs Omega Seamaster Diver 300M

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

	Omega 234.30.41.21.03.001	Omega 210.30.42.20.01.001
Model	Seamaster 300M, Modern	Seamaster Diver 300M
Caliber	Omega Cal. 8400 -- Co-Axial Master Chronometer automatic, 25,200bph, 60h PR, 30j; METAS-certified, anti-magnetic to 15,000 gauss; used in Seamaster 300 and Railmaster	Omega Cal. 8800 -- Co-Axial Master Chronometer automatic, 25,200bph, 55h PR, 30j; METAS-certified, anti-magnetic to 15,000 gauss, Naiad Lock
Case size	41mm	42mm
Lug-to-lug	46.5mm	46.5mm
Years produced	2014–present	2018–present
Brand tier	luxury	luxury
Era	modern	modern
Movement tier	In-house manufacture	In-house manufacture
Market median (excellent / full-set)	n/a	n/a
Typical range	n/a	n/a
Confidence	low	low
Categories	dive, sport	dive, sport
Editorial	yes	yes
Typical price (2026)	n/a	$4,000 – $5,500
Collector note	n/a	landmark: The 1993 relaunch of the Seamaster Professional brought Omega back into serious collector conversation and powered a decade of commercial recovery for the brand.