Croton Nivada Grenchen - Flat Top Lug Antarctic Models 1954-64
Early models are most popular with collectors having the distinctive hour markers, blued second hand, flat lugs and white sometimes textured dials, known as tundra and glacier. They capture the purity of the original concept of a rugged accurate waterproof watch able to withstand the elements.
AO V.1a Early Model - Sterile Dial circa 1954-57
With the same flat lug case and big crown as the first series, these contain an ETA with and without date dial and no Antarctic subtext. It is assumed that these were made before the US Navy 1957 DeepFreeze tour as Nivada certainly used the marketing coup associated with the expedition to its maximum on a huge variety of dials after this date. The same watch also appears with the Antarctic name in an advert. This ETA movement is mostly associated with models circa 1950-1954. The casebacks appear with various permutations of 61 and 63 so it is assumed this is the reference and the case type and movement (eg date or no date), 63L steel etc although this may be some kind of other case coding or year dating.
- Radium dial and hands
- Domed crystal with cyclops (square or round)
- 17.5mm lug width
- ETA 1258 with signed rotor
- White dial, silver furniture, blued second hand (steel on gold-cased models)
- 34mm width ex crown
- screw dodecahedron caseback with 61 or 63L engraved (steel) 63Y (20micron rolled gold)
- Larger winding crown
AO V.1a Early Model - Tundra Dial circa 1954-61
The tundra dial is a rippled effect, unique to Nivada and not seen by this author on any other manufacturers watches. It supposedly replicated snow drifts. These are most commonly seen with Antarctic script but also, in this example, with Aquamatic script and Croton Nivada Grenchen (CNG). They share the same flat lug case and big crown as the first series, ETA and normally no date. The same watch also appears with the Antarctic name. The distinctive lug shape, blue second hand and silvered numerals make these popular with collectors.
- Radium dial and handswith cyclops (square or round)
- 17.5mm lug width
- ETA 1256 with signed rotor
- White dial, silver furniture, blued second hand
- 34mm width ex crown
- screw dodecahedron caseback with 61
- Larger winding crown
AO V.1b - Circa 1956 to 1964
The Antarctic signed dial first appears, in conjunction with the US Navy Deep Freeze expedition.
- Diameter (excluding crown): 35mm
- Lug to lug: 42mm
- Lug width: 18mm
- Large crown for ease of winding whilst wearing gloves in cold conditions
- Movement: Various automatic ETA 1256, 23xx, 24xx.
- Power reserve: ~40 hours
- Case: All stainless steel, later gold plated available.
- White dial with radium lume and steel hands with lume
- Blued second hand
- Most non-date, some date versions
- Dial lettering can contain Croton, Nivada Grenchen combinations.
