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The Encyclopedia of Horology

Wristwatch · Self-winding wristwatch

Croton Nivada Grenchen Aquamatic Caliber ETA 1256 Wristwatch

Partially verified

This vintage Croton Nivada Grenchen Aquamatic wristwatch is dated by the seller to the 1950s. The source reports that it is powered by a 17-jewel Swiss automatic movement, caliber ETA 1256. The round case measures 31 mm in diameter (34.8 mm with crown) and is constructed of base metal and stainless steel with faceted angular lugs. Its light-colored dial exhibits extensive mottled age patina, luminous Arabic numerals at the three-hour positions, dart hour markers, and matching hands. The dial is signed 'CROTON NIVADA GRENCHEN' and 'AQUAMATIC'.

Front three-quarter view of the Croton Nivada Grenchen Aquamatic showing dial patina and case lugs
Front three-quarter view of the Croton Nivada Grenchen Aquamatic showing dial patina and case lugs — Secondhand Horology. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
secondhandhorology.com
Category
Wristwatch · Self-winding wristwatch
Maker / attribution
Croton Nivada Grenchen
Reference
61S6935
Catalogue / lot identifier
WA-3610
Source-reported date
1950s
Country
Switzerland

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Exterior Construction

The watch features a round case constructed from base metal and stainless steel, distinguished by angular, stylized lugs extending from the polished body. Dimensions provided by the seller include a 31 mm diameter (34.8 mm including the crown), a lug-to-lug span of 37.4 mm, a thickness of 10.6 mm, and a 16 mm lug spacing.

The case back markings, as reported by the vendor, transcribe Swiss patent references and specifications stating: 'Nivada S.A. Grenchen CROTON Base Metal Swiss Brev. N 189190 1878014 Stainless Steel Selfwinding Waterproof Incabloc 61S6935'.

Evidence for this section
  • “Cased in a 31mm round case and fancy lug design, base metal and stainless steel.”
  • “Nivada S.A. Grenchen CROTON Base Metal Swiss Brev. N 189190 1878014 Stainless Steel Selfwinding Waterproof Incabloc 61S6935”

Dial and Hands

The dial displays a light champagne tone showing mottled age and surface wear across its center. It is configured with luminous Arabic numerals at the cardinal positions 12, 3, 6, and 9, interspersed with luminous dots and silver triangular dart hour markers, enclosed by an outer minute track.

Branding is printed directly on the dial surface, signed 'CROTON NIVADA GRENCHEN' below the 12 o'clock position and 'AQUAMATIC' above 6 o'clock. The time is indicated by luminous matching hands paired with a center sweep second hand.

Evidence for this section
  • “It still has the original champagne dial (showing age and patina) featuring luminous Arabic Numerals, luminous dots and silver hour markers, bold minute track and luminous matching hands.”
  • “The dial is also signed with the Croton Nivada Grenchen name/logo on top and Aquamatic on the bottom.”

Reported Movement and Technical Data

According to the seller's cataloging, the watch is powered by an automatic self-winding movement identified as an ETA caliber 1256 operating at 18,000 A/h with 17 jewels and a 42-hour power reserve. The listing notes the ETA 1256 (Etarotor) as the first automatic movement from ETA.

The internal mechanism markings are reported by the vendor as 'Croton Nivada SA. Grenchen Seventeen 17 Jewels Unadjusted Swiss Cal. ETA 1256 E3SE C2306'. However, because movement photographs are omitted from the source record, these mechanical specifics remain seller-reported rather than independently confirmed.

Evidence for this section
  • “original Croton - Nivada Grenchen automatic movement, caliber ETA 1256, 17 jewels, sweep second-hand, 18,000 A/h, 42 hours power reserve, Swiss made.”
  • “Movement: Croton Nivada SA. Grenchen Seventeen 17 Jewels Unadjusted Swiss Cal. ETA 1256 E3SE C2306”

Open research questions

  • Can direct photography of the ETA 1256 movement verify the reported import/caliber stampings ('E3SE C2306') and physical condition of the rotor?
  • What specific production year corresponds to patent numbers Brev. 189190 and 1878014 inscribed on the case back?
  • Does the luminous material on the dial and hands consist of original radium compound consistent with 1950s Swiss manufacture?

Source evidence

Recorded claims and source quotations for Croton Nivada Grenchen Aquamatic Caliber ETA 1256 Wristwatch
FieldSource-reported valueSource quotation
CaliberETA 1256“caliber ETA 1256, 17 jewels”
Case Diameter31 mm“Cased in a 31mm round case”
Lug Width16 mm“Lug Width 16”
Case Back Reference61S6935“61S6935”
SKUWA-3610“SKU: WA-3610”
Case Thickness10.6 mm“Case Thickness 10.6”
Lug to Lug37.4 mm“Case Lug to Lug 37.4”
Case Diameter with Crown34.8 mm“Case with Crown 34.8”
Vibration Rate18,000 A/h“18,000 A/h”

Visible details

  • Patinated light-toned dial showing mottling and surface wear across the center.
  • Geometric stylized lugs extending from the polished round case.
  • Arabic numerals at 12, 3, 6, and 9 paired with triangular dart markers.
  • Signed 'CROTON NIVADA GRENCHEN' below 12 and 'AQUAMATIC' above 6.

Research qualifications

  • Movement caliber ETA 1256 and internal case markings rely on seller description as movement photography is not shown.
  • Fitted with an aftermarket replacement leather strap.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Shop Vintage Croton Nivada Grenchen Aquamatic Watch – SECOND HAND HOROLOGY

Reviewed 2026-10-21 · Record 59652fb543

Terms in this record

Glossary explanations for terms named in this object’s record.

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