
48 watches that match on case size, movement family, and price band. Sorted by how close the match is.
The closest alternative to the RGM Watches Model 300 Divers is the Sinn U18 ($3,488) — shared caliber (Sellita SW300-1) and Pro diver. If price is the constraint, the Invicta Pro Diver 36972 covers most of the same brief. From the independents, the Zelos Hammerhead V3 300m is the standout microbrand take — pro diver and Looks nearly identical.
Independent makers covering the same brief, usually with something the mainstream brands don't.
Established brands covering the same brief at a comparable price: same case size, similar movement family. Often the deciding click for a new buyer.
If the price is the only thing keeping you off this watch, these get you most of the way there for less.
Where the same idea goes when budget isn't the constraint: luxury upgrades and step-ups.