Super Compressor: the 2026 Collector’s Field Guide to EPSA Dive Case — Identification, Authentication and Value

Count the crowns. Read the caseback. Then talk about price.A case that seals harder the deeper you go. Twin crowns, a bezel under the crystal, and a slim profile you could wear with a suit. EPSA of Bassecourt patented it in 1956 and made it for two decades, selling it to a hundred different brands.Everyone wants the look. Few know what they are actually buying.The Super Compressor is the most misunderstood case in vintage watch collecting. Sellers apply the name to three different EPSA cases and to modern watches that have none of them. This field guide fixes that - in plain English, with a checklist you can run in sixty seconds at a fair.What is inside: - How the case actually works, and why deeper means tighter- The three EPSA case types - and which one is the diver- The six-point checklist: caseback, crowns, internal bezel, seal, dial and hands, coherence- Genuine EPSA against "compressor-style" - and the exact words sellers use to blur the line- Spotting a Franken-watch, and why the commonest case is not a fake but a genuine watch described as something better- A brand directory, from the blue-chips to the lost names- What drives value, where the market sits in 2026, and where the best risk and reward actually is- Care, servicing, straps - and the honest position on water- 27 figures, 26 of them original technical drawings made for this bookFor collectors of vintage divers, for anyone about to buy one, and for anyone who has ever wondered whether the watch in front of them is the real thing.Independent and unaffiliated. Not authorised or endorsed by any watch manufacturer. Brand names are used descriptively for identification only.