SpecStudio
Click to inspect
Seiko Monster
$550Stock unknown
Case
- Diameter
- 42.4mm
- Thickness
- 13.4mm
- Lug-to-lug
- 49.4mm
- Lug width
- 20mm
- Material
- Stainless Steel
- Water resistance
- 200m
Crystal & dial
- Crystal
- Hardlex
- Lume
- LumiBrite on hands, index(es) and bezel
Movement
- Caliber
- Seiko 4R36
- Type
- Automatic
- Power reserve
- 41h
- Jewels
- 24
Seiko
Seiko's day-date automatic caliber and the in-house branded version of the NH36 with stricter quality control and finishing. The additional day wheel over the 4R35 adds the day-of-week complication without changing the movement dimensions. Found extensively in the Seiko 5 Sports and Prospex lines, it offers Seiko's proven reliability with the convenience of day-date display at a mainstream price point.
Design language
- Case shape
- round
- Dial style
- matte
- Bezel
- rotating
- Bracelet
- lug-attached
- Hands
- mercedes
AI-detected from the product image
Prospex Sea collection · 33 watches
20 more in this collection
Prospex Sea 1965 Heritage Diver's WatchProspex Sea 1965 Heritage Diver's Watch PADI Special EditionProspex Sea 1968 Heritage Diver's GMTProspex Sea 1968 Heritage Diver's GMT WatchProspex Sea 1968 Heritage Diver's GMT Watch Limited EditionProspex Sea 1970 Heritage Diver's Black Series Limited EditionProspex Sea 1970 Heritage Diver's Save the Ocean Special EditionProspex Sea JAWS 50th Anniversary Limited EditionProspex Sea PADI Special EditionProspex Sea PADI Special EditionProspex Sea PADI Special EditionProspex Sea PADI Special EditionProspex Sea Save the Ocean Special EditionProspex Sea Save the Ocean Special EditionProspex Sea Save the Ocean Special EditionProspex Sea Seiko Diver’s Watch 60th Anniversary Limited EditionProspex Sea Seiko Diver’s Watch 60th Anniversary Limited EditionProspex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited EditionProspex Sea The Black SeriesSumo
The market
Market prices.
Retail$550
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.
Retail stock & market context
Seiko on the secondhand market
+10.5%
2026 so far · +5.8% to +16.3% · 91 matched watches
In line with the index
Divers as a group: +6.5% · 339 matched watches
Year-by-year readings →The connection engine
More like this.
The community take
Owners talk.
Owners widely praise the Seiko Prospex Sea for its excellent value, robust build, and superb lume, with many noting its comfortable wearability. Reviewers consistently highlight its impressive finishing and classic dive watch design, often comparing it favorably to older models. Some owners find the size substantial, with one noting it as big, thick, and heavy on a 6.5-inch wrist, while others find it perfect. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its exceptional value and robust, classic dive watch design.
Open the discussion
On real wrists
No shots yet. Show how it wears.
The paper trail
The discussion