Swatch’s $400 sequel to the MoonSwatch is inspired by sea slugs and ditches quartz for the budget brand’s automatic movement.

Looking to follow up on the staggering success of its Omega MoonSwatch collaboration, Swatch Group has announced its next in-house mashup, the Swatch x Blancpain Scuba Fifty Fathoms, or “Scuba Fifty,” and it drops this weekend.

Named after Swatch’s ’90s Scuba divers and Blancpain’s Fifty Fathoms dive-watch range, the new collection takes inspiration from the luxury brand’s timepiece that set the blueprint for analog dive watches as we know them.

The original Fifty Fathoms was developed with the help of French combat divers who needed a tough, reliable underwater wristwatch, so a piece with luminous dial markings, innovative waterproof construction, and locking rotatable bezel was created. Rolex’s Submariner, developed the same year, took the same approach—but only made it to market the following year.

The $400 (£340) Scuba Fifty Fathoms, all water-resistant to 91 meters, or 300 feet (exactly 50 fathoms, naturally), mirror the MoonSwatch collection’s bright coloring and use of Swatch’s Bioplastic material for the casings. They differ, though, when it comes to the innards: While the chronograph MoonSwatch is powered by an electronic quartz mechanism, the Scuba Fifty Fathoms boasts a self-winding automatic movement, taken from Swatch’s innovative Sistem51 line. Blancpain, a key player in the revival of Swiss watchmaking in the 1980s and ’90s, is one of few Swiss brands never to have made a quartz-powered wristwatch, sticking solely to mechanical watchmaking; so it continues to be, even when it appears in Swatch form.

But unlike the 11 iterations of the MoonSwatch (not counting the later pimped Moonshine Gold versions), Swatch’s Blancpain collaboration will feature five watches, each named after one of the world’s oceans.

The green Indian, blue Atlantic, and yellow Pacific models refer to more modern Fifty Fathoms iterations, while the red Arctic and white Antarctic models hark back to renowned and very rare versions commissioned for military purposes in the 1960s: the Arctic model is inspired by the so-called “No Rad” Fifty Fathoms, recognizable for a prominent dial marking indicating no radioactive materials present in the watch’s luminescent markings (it had only recently become apparent how dangerous radium, traditionally used, in fact was); while the Antarctic watch refers to “Mil-Spec” (military specification) models made for the US military, with an esoteric indicator on the dial for moisture ingress.

Inspired by Sea Slugs!

Gregory Kissling, Omega’s head of product and the person drafted in to helm the development of the MoonSwatch, has stated that the colors of the Scuba Fifty Fathoms are not only all new Bioceramic colors, but that each watch’s hue is inspired by a nudibranch, a type of sea slug, that is native to that particular ocean.

Thousands of species of nudibranch are found in the world’s oceans, and so Swatch and Blancpain decided it would not only chime with Blancpain’s environmental commitment to the oceans but also continue the bright aesthetic of the MoonSwatch to select five colorful varieties of the marine mollusc to inspire the tint of its new watches.

When the Scuba Fifty Fathoms go on sale in Swatch stores on Saturday, perhaps eager buyers will have learned the lessons from the Omega collaboration rollout and exercise some patience. It may be some time before Blancpain’s MoonSwatch moment becomes widely available.

The $400 Scuba Fifty will be sold in the following US Swatch stores: Ala Moana in Hawaii, NY NY in Las Vegas, 5th Ave and TSQ in New York, Powell in SFO, Houston Galleria, Lincoln Road in Miami, Millenia in Orlando, and NorthPark in Dallas.