Seiko Nautilus Mod (Nautiko) – Open Heart Royal Blue
Seiko Nautilus Mod (Nautiko) – Open Heart Royal Blue
Made to be looked at twice.
Genuine Seiko movement, sapphire crystal and a solid stainless steel case. Built to wear every day.
Watch sizing
| Case size | Suits wrists | How it wears |
|---|---|---|
| 36 mm | 14–17 cm | Slimmer and dressier |
| 39–41 mm | 16–20 cm | The classic full look |
Every bracelet adjusts to your wrist with the included screwdriver. If you're between sizes, pick the look you prefer.
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Change your mind within 24 hours of ordering? Full refund, no questions.
Faulty or not as described? Repaired, replaced or refunded.
Every watch ships with a travel case + sizing tool.
Royal blue, with a window cut straight through to the movement.
The dial is deep blue and perfectly still until the light moves across it, and near the top there is an opening where the balance wheel swings back and forth all day long. A silver bezel and a link bracelet keep everything else quiet so the moving part stays the star. The design it echoes sits behind jeweller's glass.
People stopped noticing watches years ago. They still notice movement. This one pulls eyes across a table, and then you go back to your coffee like nothing happened.
An open heart only works when the heart is real
The Seiko NH38 automatic runs at 21,600 beats per hour, hacks its seconds when you pull the crown, takes a hand-wind whenever you want one, and holds about 41 hours of power reserve. It carries no date, which is what clears the space for the open heart. No battery, ever.
Around it: a sapphire crystal that shrugs off keys and door frames, and a blue dial opened at the front so the mechanism is something you look at rather than something you take on trust.
| Movement | Seiko NH38 automatic, open heart, no date, 21,600 bph, approx. 41-hour power reserve |
| Dial | Blue, open heart aperture |
| Bezel | Silver tone |
| Bracelet | Metal link |
| Crystal | Sapphire |
| Water rating | 5 ATM |
What this price actually buys
The watch this design echoes sells for hundreds of times this price, and a routine service on it costs more than this entire watch. Here, one price buys the whole thing: a genuine Seiko automatic under sapphire, built to order for you and regulated by hand. Nobody needs to know what it cost. That part is yours.
Order yours and start your build. You will get photos of your finished watch before it ships. Then you will get the watch.
What's included
What's included
Every order arrives with your watch, a travel case and a sizing tool for adjusting the bracelet. Inspected before dispatch and backed by a 1-year warranty.
Sizing & fit
Sizing & fit
Stainless steel case and bracelet. Where more than one case size is offered, choose yours from the size selector above. Smaller sizes suit slimmer wrists, larger sizes wear with more presence. A screwdriver is included so you can adjust the bracelet links to your wrist at home. Not sure which size suits you? Message us before you order and we will help.
Shipping & returns
Shipping & returns
Every watch is made to order, with free worldwide shipping. Build and dispatch times are set out in our Shipping Policy. Because each watch is built to the specification you choose, we do not accept returns for change of mind. Changed your mind before we start? Email us within 24 hours of ordering and we will cancel and refund you in full. If anything is wrong with your watch we fix it: a fault, transit damage or the wrong model is repaired, replaced or refunded, and we pay the postage both ways. Orders outside Australia may attract import duty, tax or VAT on arrival. These are set by your local customs authority and are the customer's responsibility.
Warranty
Warranty
Backed by a 1-year warranty against manufacturing faults in the movement, crystal, case and dial. Faulty or not as described? We repair, replace or refund at no cost to you.
What is a Seiko mod?
What is a Seiko mod?
A watch built on a genuine Seiko automatic movement (the NH-series mechanical calibre Seiko uses in its own watches), fitted with a custom case, dial, hands and bracelet in a design inspired by iconic timepieces. Self-winding, no battery, serviceable for decades. It's not a copy of anyone's watch and we never pretend otherwise: it's the mechanical heart you want, without the luxury markup. Read the full story.
Nautilus (Open Heart, Royal Blue) | NH38 Custom Mod Watch
How it works
Questions people ask before ordering
Is this a real watch or a fake?
It is a real watch and an original Rosevari build. Inside is a genuine Seiko automatic movement; the case, sapphire crystal and dial are parts we choose and stand behind. A fake is sold as the genuine article. Every Rosevari is sold openly as exactly what it is, a custom Seiko mod, with every part disclosed.
Is it automatic?
Every watch runs a genuine Seiko movement. GMT models use the self-winding NH34 automatic with an independently set GMT hand, datejust styles use the NH35 automatic, and chronograph builds use the VK63 meca-quartz. The exact movement for this watch is named in the specifications above.
How much does it cost?
This build is $349.00 AUD with free shipping. Prices are shown in Australian dollars for Australian customers, and there are no extra charges at checkout for AU orders.
How long until it is on my wrist?
Every watch is made to order. Build and dispatch times are set out in our Shipping Policy. If it arrives faulty, damaged in transit, or not what you ordered, we repair, replace or refund it and pay the postage both ways.