Isotope · Microbrand · United Kingdom

Isotope Hydrium (Landeron 24)

Limited · Diver

Isotope Hydrium California, black California dial
Photo: Isotope
  • Isotope Hydrium Grey Reef Shark, grey dial
  • Isotope Hydrium NASA, off-white dial, white strap
  • Isotope Hydrium Revuelta Amarillo, yellow dial
  • Isotope Hydrium Revuelta Azul, blue dial
  • Isotope HydriumX BSMH Blue, blue sunburst dial
  • Isotope HydriumX Will Return, white dial, light blue bezel
  • Isotope Hydrium Burnt Tangerine, orange dial
  • Isotope Hydrium Blue Night, black enamel dial
  • Isotope HydriumX Blink, pink dial, blue bezel
  • Isotope HydriumX The Judge, black dial, red bezel
  • Isotope Hydrium Alba, white enamel dial
  • Isotope HydriumX Exit, off-white dial, green bezel
  • Isotope Hydrium Pro Nordblad, black dial
  • Isotope Hydrium Seconde/Seconde/, black dial
  • Isotope Hydrium Pro NSFW Purple, purple dial
  • Isotope HydriumX Will Return Red, white dial, red bezel
From $725 to $1,733
  • Landeron 24
  • 40 mm × 14.9 mm
  • Sapphire crystal
  • 300 m water resistance

Movement

Type
Automatic
Tier
Upper
Complications
Hours, Minutes, Seconds
Frequency
28,800 bph
Power reserve
40 h
Hacking
Yes
Accuracy (factory)
—
Brand regulation
-12 / +12 s/day
Modifications
Customised finishing with blued screws, perlage and Côtes de Genève; custom rotor

Case

Diameter
40 mm
Lug to lug
48 mm
Thickness
14.9 mm
Lug width
22 mm
Material
Steel (316L)
Hardening
—
Water resistance
300 m
Crown
Screw-down
Case back
Display, screw-down
Bezel
Unidirectional, 120 clicks
Finishing
Micro-blasted (Cerakote coating on some editions)

Crystal & dial

Crystal
Sapphire
Shape
Double-domed
Anti-reflective
Yes (side not stated)
Lume
Super-LumiNova

Bracelet & clasp

Style
—
Links per row
—
Solid end links
—
Solid links
Yes
Link attachment
Screws
Taper
22 → 18 mm
Quick release
Yes
Half links
—
Clasp
—
Micro-adjust
On-the-fly
Diver extension
—

Straps

Strap 1
FKM rubber, quick release, 22mm (or 22/20mm) quick-release FKM, most editions; some add suede, leather, Z.A. single-pass or NASA straps

Weight

Head only
—
On bracelet
—
On strap
—

Prices

VariantConfigurationTypePriceUSDAs ofSource
California—Msrp1,100 GBPincl. VAT$1,4662026-10-24link
Grey Reef Shark—Msrp1,300 GBPincl. VAT$1,7332026-10-24link
NASA—Msrp1,100 GBPincl. VAT$1,4662026-10-24link
Revuelta Amarillo—Msrp1,100 GBPincl. VAT$1,4662026-10-24link
Revuelta Azul—Msrp1,100 GBPincl. VAT$1,4662026-10-24link
BSMH Blue—Msrp1,100 GBPincl. VAT$1,4662026-10-24link
HydriumX Will Return—Msrp563 GBPincl. VAT$7512021-12-07link
Burnt Tangerine—Msrp544 GBPincl. VAT$7252021-12-07link
Blue Night—Msrp563 GBPincl. VAT$7512021-12-07link
HydriumX Blinkexcluding UK VATMsrp617 GBPincl. VAT$8222022-07-20link
Alba—Msrp840 GBPincl. VAT$1,1202022-11-29link
HydriumX Exitwhite or grey FKM strapMsrp840 GBPincl. VAT$1,1202023-03-16link
HydriumX Exitblack leather strap with green stitchingMsrp880 GBPincl. VAT$1,1732023-03-16link
Seconde/Seconde/excluding UK VATMsrp900 GBPincl. VAT$1,2002023-05-31link
HydriumX Will Return Redincluding UK VATMsrp1,000 GBPincl. VAT$1,3332024-03-03link

Variants

NameDialBezelConfigurationStatus
Californiablack textured California (Roman and Arabic numerals)—black FKM strapLimited (200)
Grey Reef Sharkcold grey with raised Lacrima motif—Hydrium bracelet and grey FKM strapLimited (200)
NASAoff-white, full lume—Cerakote-coated case; white FKM and NASA strapsLimited (200)
Revuelta Amarilloyellow—yellow FKM strapLimited (50)
Revuelta Azulmatte blue—blue FKM strapLimited (50)
BSMH Blueblue sunburst—black leather strap and blue FKM strapLimited
HydriumX Will Returnglossy white full lume with red Lacrima handslight blue with red LacrimaFKM strapLimited (100)
Burnt Tangerineburnt tangerine with raised Lacrima and index ring—solid screw-down caseback with diving motif; FKM strapLimited (100)
Blue Nightdeep black enamel with blue flamed hands—solid screw-down caseback; FKM strapLimited (100)
HydriumX Blinkshimmering pink salmon—blue FKM strapLimited (100)
HydriumX The Judgeblack with white numerals and red handsred with Lacrimablack FKM strapLimited (100)
Albapure white enamel with blue railroad track and heat-blued handsblacksolid screw-down caseback with embossed diving helmet; blue FKM strapLimited (100)
HydriumX Exitoff-white full lume with running figure and green handsgreenwhite or grey FKM strap, or black leather with green stitchingLimited (100)
Pro Nordbladmatte black with white numerals and blue seconds hand—black FKM strapLimited (100)
Seconde/Seconde/matte black with green accents, OTOPSIE logoblack with green Lacrimablack leather strap with green stitchingLimited (50)
Pro NSFW Purpleroyal purple with white numerals and orange seconds hand12-hour scaleblack leather strap with purple stitching plus orange FKM strapLimited (100)
HydriumX Will Return Redwhite full lume with black numerals and red handsred with lumed white Lacrimalight blue FKM strapLimited

About this entry

79% of key specs known. Missing: weight, hardening, bracelet links, end links.

The Hydrium dive watch with the Swiss Landeron 24 automatic (25 jewels, 28,800 A/h, 40h; Isotope quotes -12/+12 s/day). Isotope names the Landeron 24 on the Grey Reef Shark page and Monochrome's review of the California names it too; the other pages say "Swiss Landeron" with the same specs. The movement's date is not shown (Monochrome: Isotope dropped the date at 3 for a time-only dial). The same case with the La Joux-Perret G101 Soigné is a separate model, hydrium-g101; edition sizes cover both builds. Shared spec table: micro-blasted 316L steel, 40mm and 48mm with lugs, 12.9mm case height and 14.9mm with the double-domed sapphire (Monochrome and Worn & Wound give the same 48mm and 14.9mm), AR sapphire, screw-down exhibition caseback (solid on Burnt Tangerine, Blue Night and Alba), 120-click unidirectional bezel, screw-down crown at 3, 300m, Super-LumiNova, 22mm lugs. Editions: Grey Reef Shark 200 pieces (2026; bead-blasted Hydrium bracelet with solid screw links and diver's clasp with micro-adjustment, plus grey FKM strap), California 200, NASA 200 (Cerakote-coated case), Revuelta Amarillo and Azul 50 each; the HydriumX BSMH Blue is a special edition of unstated size. Older sold-out editions, listed without a price and all with the same 40mm x 48mm, 14.9mm spec table and Landeron movement: HydriumX Will Return (2021, 100 pieces, selected for the 2022 GPHG; £563 per Oracle of Time), Burnt Tangerine and Blue Night (2021, 100 each, solid casebacks; £544 and £563 per Oracle of Time, which also says "priced around the £450 with Miyota movements", contradicting Isotope's Swiss Landeron spec), HydriumX Blink (2022, 100; GBP 617 excluding VAT per Monochrome), HydriumX The Judge (2022, 100; no price found), Alba (2022, with Scottish Watches, 100; white enamel dial, solid caseback with an embossed diving helmet; £840 per Oracle of Time), HydriumX Exit (2023, 100; £840 on FKM or £880 on leather per Oracle of Time), Hydrium Pro Nordblad and Pro NSFW Purple (2023, 100 each; Isotope says the Pro exceeds ISO 6425, but its spec table is the same as the other Hydriums; no prices found), Seconde/Seconde/ (2023, with Romaric André, 50; £900 excluding VAT per Fratello) and HydriumX Will Return Red (2024). The Will Return Red was sold only in a March 4-10, 2024 order window: the page text says it is not a limited edition, but its spec heading says "limited to 50 units", so no edition size is recorded; Fratello gives £1,000 including UK taxes. Its listing also sold the Wall Return, a 35cm aluminium wall clock with a Seiko quartz movement, alone or in a bundle with the watch (Worn & Wound: £940 outside the UK); the clock isn't recorded. Prices marked "excluding UK VAT" are as the source gave them. The Orange One's page lists its Landeron option as no longer available, but the 2026 Grey Reef Shark uses the Landeron 24 and the Revuelta Amarillo's Landeron option was in stock on 2026-10-25; the other Landeron options were sold out. Bracelet details are from the Grey Reef Shark page and the separately sold Hydrium S.S. Bracelet (£268, 22mm tapering to 18mm). Isotope's store prices include UK VAT. Weight isn't published.

Last verified: 2026-10-25. Edit or correct this entry.

Sources