The Black Bay GMT blends the advantages of the Black Bay diving watch with the practicality of displaying three time zones at once. Its blue and red 24-hour bezel and in-house caliber make it an attractive alternative to the Rolex GMT-Master II.

By Chrono24

This page contains information about:

A Diving Watch With a GMT Function and Pepsi Design

Tudor added the Black Bay GMT to its beloved diving watch collection in 2018. This model is capable of displaying up to three times zones at once. The Swiss manufacturer clearly took inspiration from one of its sister company's most iconic watches, the Rolex GMT-Master, when designing this timepiece.

The Black Bay GMT even shares a color scheme with its famous Rolex cousin. Both feature a bidirectional 24-hour bezel in the beloved blue and red "Pepsi" design. The dial is either matte black or opaline with a date display at 3 o'clock. While most of the hour markers are luminous dot indices, there are rectangular bar indices at 6 and 9 o'clock, as well as an inverted triangle at the top of the hour.

That being said, the Black Bay GMT is anything but a copy of the GMT-Master. It boasts everything that makes the Black Bay collection so popular, including a 41-mm stainless steel case, large crown without a crown guard, and domed sapphire crystal without a magnifying lens. Perhaps the most notable feature that sets this model apart is its square-tipped "snowflake" hands. What's more, the Black Bay GMT is water-resistant to 200 m (20 bar, 656 ft), while the GMT-Master II is only rated to 100 m (10 bar, 328 ft).

The Tudor in-house caliber MT5652 powers the Black Bay GMT. Paired with the bezel, it can display up to three time zones simultaneously. It also has a 70-hour power reserve and comes with chronometer certification from the Official Swiss Chronometer Testing Institute (COSC).

Reasons to Buy a Black Bay GMT

Highly popular "Pepsi" design
Displays up to three time zones simultaneously
COSC-certified in-house caliber MT5652
Water-resistant to 200 m (20 bar, 656 ft)
Black or opaline dial

Price Overview: Tudor Black Bay GMT

Reference number	Price (approx.)	Dial color, band
M79830RB-0010	4,500 USD	Opaline, three-piece riveted stainless steel bracelet
M79830RB-0012	4,000 USD	Opaline, black fabric strap with pin buckle
M79830RB-0001	4,200 USD	Black, three-piece riveted stainless steel bracelet
M79830RB-0003	3,600 USD	Black, black fabric strap with pin buckle

How much does a Tudor Black Bay GMT cost?

As of August 2023, the most affordable Tudor Black Bay GMT is the reference with a black dial and fabric strap. Prices come in around 3,600 USD for mint-condition copies. Pairing the model with a stainless steel bracelet will raise the required investment to 4,300 USD. The Black Bay GMT with an opaline dial from 2023 is a bit more expensive: This Tudor watch costs 4,500 USD on a stainless steel bracelet and 4,000 USD on a fabric strap.

Design Details

The Black Bay GMT measures 41 mm in diameter. Its stainless steel case is satin-brushed on both the top and bottom, while the polished sides add a touch of elegance. The bezel is also made of stainless steel. It features a 24-hour track with a red and blue anodized aluminum inlay.

The reference number M79830RB-0001 has a black dial and comes on a stainless steel link bracelet. Like the case, the bracelet links have brushed tops and bottoms and polished sides. The designers decided to mimic the look of the riveted bracelets popular in the 1950s and 60s. However, the Black Bay's links actually screw together, so the rivets are purely decorative. Plan to spend about 4,200 USD on a new timepiece. If you'd like the version with an opaline dial (ref. M79830RB-0010), you'll need to invest around 4,600 USD.

Tudor pairs the Black Bay GMT ref. M79830RB-0003 with a black fabric strap. A red line runs down the strap's center for an extra sporty touch. Unlike the steel and leather editions, which both use a folding safety clasp, the textile strap comes with a stainless steel pin buckle. Prices for this model sit around 3,600 USD. Once again, the opaline dial version is more pricey. You will find this model under the reference number M79830RB-0012 on a fabric strap for around 4,000 USD (as of August 2023).

About the In-House Caliber MT5652

Tudor developed the caliber MT5652 specifically for the Black Bay GMT. This movement is based on the in-house caliber MT5602, which first appeared in 2015. It ticks at a frequency of 28,800 vibrations per hour (vph) and has a 70-hour power reserve. It's also resistant to strong magnetic fields thanks to its silicon balance spring. Not even strong jolts can knock this movement out of sync, since its balance is held in place by bridges instead of conventional balance cocks. The MT5652 is also a COSC-certified chronometer, meaning it is extremely accurate.

Tudor has put just as much care into the caliber's GMT function. Like its Rolex counterpart, the MT5652 enables the wearer to set local and home time zones separately. For example, to adjust the local time, you simply pull the crown out to its first position to move the hour hand forward or backward in one-hour increments without having to stop the watch completely. The movement is even able to account for date changes.