Challenger Automatic Spinnaker's bubble-dome diver shrunk to 42 mm

What is new about the Challenger Automatic?

The Challenger Automatic is a 2025 addition to Spinnaker's dive range, and the brand calls it a "Piccard Junior". The Piccard made its name with a huge bubble-dome sapphire crystal on a 45 mm case. The Challenger keeps that idea and shrinks it to 42 mm, which makes the look far easier to live with.

The name comes from the Challenger Deep, the lowest point of the Mariana Trench. Spinnaker leans into the theme with a 3D-moulded dial that is meant to suggest the texture of the ocean floor, plus a deep-etched caseback. The SP-5159-22 is the Sea Green version: a green textured dial, a green ceramic bezel insert, a steel bracelet and a matching green rubber strap in the box. Spinnaker's UK product listing went live in April 2025, alongside Depth Blue, Fiery Red and Mist Grey versions.

The basic recipe is classic. You get a unidirectional rotating bezel, a screw-down crown, applied indices with Swiss Super-LumiNova and 300 m of water resistance. The dome is the hook.

How big is it, and how will it wear?

Spinnaker quotes a 42 mm case, 49.5 mm lug to lug and 19 mm thick. That last figure needs context. Almost all of the height is the domed crystal, which rises well above the bezel. Chronos Japan measured 18.5 mm and described the lugs as curving towards the wrist, which helps the fit.

So the footprint is a normal mid-size diver. The 49.5 mm lug to lug will suit most wrists from about 16.5 cm up. The height will not hide under a shirt cuff, and it is the first thing people notice. Weight is 170 g on the bracelet, by Spinnaker's figure, which is solid but not heavy for a steel diver of this size.

The bracelet is 20 mm wide with a fold-over clasp, safety lock and push buttons. The included rubber strap is the lighter option for summer or swimming. Spinnaker includes both, so there is no extra strap to budget for.

What movement does it use, and how accurate is it?

This is the one area where the published details disagree. Spinnaker's own product page lists a Miyota 8215 with 21 jewels and a 42 hour power reserve. UK retailer Serious Watches, Chronos Japan and Worn & Wound all name the Seiko NH35 instead, with 24 jewels and around 41 hours.

Both are Japanese automatics running at 21,600 vph, and both are cheap and easy to service. The practical difference is that the NH35 hacks and can be hand-wound, while the Miyota 8215 cannot hack. If that matters to you, check the caseback or ask the seller before buying.

Neither calibre is a precision movement. Fratello quotes a standard tolerance of -20 to +40 seconds a day for the NH35, and the Miyota 8215 has a similar wide tolerance. Expect to reset the time now and then.

How well is it built?

The specification is strong for the money. The crystal is sapphire with an anti-reflective coating, the bezel insert is ceramic, the crown screws down and the case is 316L steel. A 300 m rating is more than most buyers will ever need.

Chronos Japan praised the satin case with polished edges and called the overall construction solid. Owners on Dialicious who have the Popeye edition of the same case report a firm bezel action with confident clicks and a reassuring crown. One small trade-off of the dome: it picks up reflections from every angle, though Chronos Japan notes that reading straight on there is no distortion.

Spinnaker offers a two year international warranty.

Is it good value against its rivals?

Spinnaker's UK site lists the SP-5159-22 at £237. It also shows a crossed-out £407, but every Challenger is listed at the lower figure, so treat £237 as the real RRP.

At that price the obvious rival is the Timex Deepwater Reef 200 on a steel bracelet (TW2W95200), with an RRP of £200. It is a 41 mm quartz diver with sapphire and 200 m of water resistance. It is cheaper and quartz-powered, so it never needs winding, but Timex does not list a ceramic bezel and you lose the automatic movement.

The other comparison is inside Spinnaker's own range. The Spinnaker Piccard (SP-5098-22) is £273 on the UK site, with a 45 mm case, 52 mm lug to lug, 21 mm of height and 550 m water resistance. If you want the bubble dome but not the bulk, the Challenger is the more sensible pick.

For an automatic with sapphire, ceramic, 300 m and two straps, £237 is fair. You are paying for design and spec, not for heritage or a finely finished movement.

What is the catch?

The catch is the height. At 19 mm, this is a tall watch, and the dome will catch on doorframes and cuffs more than a flat-crystal diver would. Some people love that porthole look; others will find it awkward in daily wear.

The second catch is the movement confusion. It is not a deal-breaker, but a brand should state its calibre clearly, and here its own page and its retailers disagree.

Finally, Spinnaker is mainly sold direct and through online stockists in the UK. You are unlikely to find one to try on in a high street jeweller, so check the return policy before you order.

“A normal mid-size diver from above, a porthole from the side.”

What do owners say?

Themes from public owner feedback, paraphrased. We never copy Amazon reviews or ratings.

• Owners of the Popeye edition, which shares the Challenger case, describe a solid case and a firm bezel with confident clicks.

  Dialicious owner review (opens in a new tab)

• The same owner calls the domed crystal a highlight but notes it is hard to photograph under direct light, and finds the blue lume weaker than the green.

  Dialicious owner review (opens in a new tab)