The Grand Seiko GMT you can dive with. Three time zones, 200 metres.

Most Grand Seiko GMTs are dress watches with a 24-hour ring on the dial; the SBGJ237 is the sports one, with a rotating ceramic 24-hour bezel, so the 24-hour hand reads home time against the dial ring and a third zone against the bezel, and a case rated to 200 metres with a screw-down crown. The 9S86 inside is the Hi-Beat 36,000 with a jumping local hour, so you land, click the hour forward and the date follows.

At 44.2mm and 188 grams it is a big watch; the 50.6mm lug to lug is the number to check against your wrist.

The listing carries the reference SBGJ237 in the title and model row and calls it a Mechanical Hi-Beat 36000 GMT Triple Time Zone. The photograph shows the ceramic 24-hour bezel, blue dial, red GMT hand, date and bracelet. The size, thickness, lug to lug, calibre, reserve, accuracy, 20 bar, weight and list price are Grand Seiko’s published figures for the reference, and the Amazon price was just under that list price when read.

The dealer is Luxor Watches, a marketplace dealer, and the rows we read do not state whether the watch is new with Grand Seiko’s warranty card; ask, and ask for the box and the card. Nothing here was measured on the watch.

This is a regular Amazon listing from a marketplace seller with Amazon’s 30-day return window; it is not a Luxury Stores pre-owned unit and the seller has not published a condition. The second button opens the live search for Grand Seiko GMTs in case this one has sold.

Grand Seikos have resold for under new and close to what pre-owned buyers paid, sometimes more, sometimes less; that is a pattern, not a promise, and nothing here is investment advice.