By TLex: I'm yet to own a vintage dive watch, but I plan to put that straight in the not so distant future. Here are three that I find interesting.
1980 Panerai Prototype
© PANERAI Library
1980 Panerai Prototype designed by Alessandro Bettarini (now of Ennebi) and commissioned by the Italian Navy. It never went into production. The Ennebi Fondale and Decima Mas Strumento share its case design. The only difference is they were unable to use Panerai's patented crown locking device.
Its 47mm titanium case is water-resistant to 1000m. This is the one and only, so obtaining one is impossible, however I plan to get an Ennebi Fondale one day. It will make an excellent substitute.
Sandoz Typhoon 1000m
© Ronin Collection
Circa 1970s Sandoz Typhoon 1000m. Reminiscent of the Benrus Type I and in fact it shares the exact same crown as the Type I and Type II. Its case measures 47X43mm, is water-resistant to 1000m and houses a 17 jewels automatic Sandoz movement. You won't come across many, but if you do, can pick up a nice one for as little as 1200USD.
IWC Porsche Design Ocean 2000
1980s IWC Porsche Design Ocean 2000. The first watch to achieve such a high (2000m) depth rating and way ahead of its time in terms of styling and spec. They are always available on ebay and other online auctions. I just saw a mint one going for 4000USD, but I know people have paid much more. A 300m Porsche Design By Eterna P6000 offers the same look for a fraction of the price, worth considering.