lug2lug
BrowseCompareNewsCommunityMy Watches
BrowseCompareNewsCommunityMy Watches
Theme
Popular microbrands:Christopher Ward·Baltic·anOrdain·Atelier Wen·Boldr·Bremont·Dan Henry·DOXABrowse all →
Best, by the specs:Diver under $2,000·Dress under $5,000·Chronograph under $5,000·Best sport watches·GMT under $5,000·Field under $500·Pilot under $2,000·Casual under $1,000All rankings →
Glossary:Lug-to-Lug·Water Resistance·Chronograph·GMT·Automatic·LumeBrowse all →
Tools:Collection tracker·Wrist-fit calculator·Selling calculator·What should I buy?·Market index·iPhone app
Lug2Letter
Watches worth knowing about, weekly.
Curated discoveries, founder spotlights, and the occasional deep-dive.
Get the app
Download on theApp StoreGET IT ONGoogle Play
TermsPrivacyDelete accountCopyrightDisclosuresContactContribute

Independent reference site · not affiliated with any brand · contains affiliate links

© 2026 Lug2Lug LLC · Prices are estimates and not offers

Loading watch
Home/Browse/Borealis Watch Co./Caloura 300m
SpecStudio
Borealis Watch Co. Caloura 300m
Click to inspect
Borealis Watch Co. · Caloura

Borealis Watch Co. Caloura 300m

Diver

$275Some sold out

Case

Diameter
42mm
Thickness
13.9mm
Lug-to-lug
44.2mm
Lug width
22mm
Material
Stainless Steel
Water resistance
300m

Crystal & dial

Crystal
Sapphire
Lume
BGW9

Movement

Caliber
Seiko NH35
Type
Automatic

Seiko

Seiko's third-party supply version of the 4R35, sold to external watch brands and modders worldwide. Adds hacking and hand-winding over the 7S26 it effectively replaced. The NH35 has become the default automatic movement for watch modding and microbrand watches, thanks to its low cost, reliability, and wide availability of compatible parts including dials, hands, and cases in the Seiko-compatible format.

Design language

Case shape
round
Dial style
matte
Bezel
rotating
Bracelet
lug-attached
Hands
baton

AI-detected from the product image

4 colorways

Alternatives

01The market

Market prices.

Retail$275

The forum market

Follow the asking price.

Active listings0Across watch forums
Closed · 90d0Asking-price history

No forum listings tracked for this watch yet. Market+ adds the weekly trend.

02The connection engine

More like this.

Spinnaker Tesei Titanium

Spinnaker

Tesei Titanium

42mm · Automatic$625

Spinnaker Hass Automatic

Spinnaker

Hass Automatic

43mm · Automatic$445

Spinnaker Hull Diver

Spinnaker

Hull Diver

42mm · Automatic$375

HELM Vanuatu

HELM

Vanuatu

42mm · Automatic$285

Zelos Swordfish 3

Zelos

Swordfish 3

40mm · Automatic$399

Aigi Watches BARENTS SEA AUTOMATIC round dive watch 43mm, applied markers + date + dive bezel

Aigi Watches

BARENTS SEA AUTOMATIC round dive watch 43mm, applied markers + date + dive bezel

43mm · Automatic$180

View all alternatives

03The community take

Owners talk.

“
In a nutshell

The Borealis Watch Co. Caloura 300m is an automatic diver watch, with a 42mm stainless steel case, 13.9mm thick, powered by the Seiko NH35 movement. Water resistance is rated to 300m, under a sapphire crystal. Manufacturer MSRP is $275.

Open the discussion

On video

On real wrists

No shots yet. Show how it wears.

04The paper trail

Ask the communityStart a discussion about the Caloura 300m: get takes from other collectors.Ask →

05The discussion

Talk about the Borealis Watch Co. Caloura 300m.