Seagull Caliber ST1961

Manufacturer	Sea-Gull
Caliber Number	ST1961, ST-1961
Base Caliber	Seagull ST1901
Movement Type	Mechanical, manual-wind, split-second chronograph
Diameter	31.3mm
Height	Unconfirmed
Jewel Count	27 jewels
Beat Rate / Frequency	21,600 bph / 3 Hz
Lift Angle	Unconfirmed
Power Reserve	39 hours
Anti-Shock Device	Incabloc style
Hand Count	6
Functions	Central hours; central minutes; central chronograph split-seconds (2 hands);small running seconds subdial at 9:00; 30 minutes chronograph counter at 3:00
Chronograph Layout	Bi-Compax
Chronograph System	Column wheel
Hacking Seconds?	No
Country of Manufacture	Made in China
Known Models	Seagull Rattrapante 70th Anniversary Limited Edition (Ref: 418.13.1077) (Add your watch to the comments below…)

The Seagull caliber ST1961 is a bi-compax mechanical split-seconds chronograph movement aka rattrapante. The calibre number comes from the year Tianjin Watch Factory (which is known as “Sea-Gull” today) was  founded: 1961.

In Seagull’s own words:

“The Seagull Rattrapante Split Second Chronograph is a rare and intricate timepiece that brings the renowned rattrapante complication within reach of a broader audience. Revered in the world of horology for its ingenuity and craftsmanship, the rattrapante function—historically reserved for the elite—has always been a symbol of luxury and precision. Now, Seagull is redefining the landscape with the most affordable rattrapante chronograph, priced at just $3,499. Powered by the newly developed ST1961 movement, this timepiece showcases exceptional craftsmanship and precision, reflecting Seagull’s commitment to quality. With only 500 pieces globally, it is a must-have for collectors and enthusiasts alike. Don’t miss the chance to own a piece of horological history.” –Source

Rattrapante:

The ST1961 is a split-seconds chronograph that allows the wearer to time two intervals at the same time. Seagull refers to this as a dual chronograph with chasing seconds hand.

How does it work?

There are two central chronograph seconds hands which are parallel to each other when in stopped position. When the chronograph is activated, both hands run in unison until the pusher at 10:00 is pressed – this action will stop the top (main) chronograph seconds hand while the bottom hand continues running. Upon pressing the 10:00 button again, the top hand will instantly catch up with the bottom hand as they continue recording the passage of time together. From there, the top right chronograph pusher at 2:00 can be pressed to pause the stopwatch function – at that point, the bottom pusher at 4:00 will reset the chronograph and return the hands to 0 position (lined up at 12:00). See the video below.

“By using the button at the 10 o’clock position, it allows for the independent stop-and-record function of the split second hand, while the main chronograph hand continues running, meeting the need to record two time points.” -Sea-Gull

No Regulator?

One thing you might have noticed with the ST1961 is that there is no visible balance wheel or regulation system. This is due to the fact that the split-seconds complication discussed above is a modular configuration that sits on top of the existing framework.

The reality is that this design will undoubtedly make it challenging to accomplish a quick adjustment of the regulator – but, the good news is that it looks like they made a cutout for access to the regulator arm – so you should have to disassemble the entire rattrapante module.

Column Wheel:

As the ST1961 movement is based on the Seagull caliber ST1901, the chronograph system uses column wheel architecture.

Video – Seagull Rattrapante Split Second Chronograph – The Most Affordable Rattrapante Chronograph Worldwide:

Notice in the video below that the dial has a printed subdial for a 12 hour chronograph counter. This is most likely just the dial they used during the prototyping process – or possibly a plan for a tri-compax version in the future.

Video – Sea-Gull 70th Anniversary: Reviving the Legacy with the Double Second Rattrapante Chronograph:

Watches with this movement:

At the time of this post, the calibre ST1961 is found exclusively in the 70th Anniversary Seagull Rattrapante Split Second Chronograh Limited Edition watch. This model features a 42.5mm titanium case, standing 16mm tall.

The Seagull Rattrapante was introduced on January 1, 2025 with only 500 pieces available worldwide.

Quick FAQs:

Can I buy a raw ST1961 movement?
At this time, the ST1961 appears to be exclusive to the Seagull Rattrapante. Wholesale movements are not available.

How much are watches with the ST1961?
The retail price listed on the official Seagull website is $3,649 USD, but the official Sea-Gull store on Aliexpress has it listed at $4,279 USD (as of 4/10/25, could it be tariff related or are they adding their Aliexpress selling fees to the price?) with a crossed out retail price of $8,558 USD.

What is the TY number equivalent?
There doesn’t seem to be one. If you come across it, please share in the comments below…

Inconsistent Information:

As is common with made in China watch movements, there is some inconsistent information floating around online.

First, is the pricing information above.

Next is the beat rate of the ST1961. The base caliber is the ST19 with a beat rate of 21,600 bph, however, on Seagull’s official landing page for their Rattrapante watch, they claim that the ST1961 beats at “28800 vibrations per hour”.

Another spec that needs confirmed is the power reserve. As seen above, Seagull quotes up to 39 hours of power reserve. Studio Underdog claims their usage of the ST1901(B) gets 45~50 hours of power reserve depending on chronograph activity. Maybe the ST1961 is quoted at 39 hours based on using the dial chronograph, but again, this is unconfirmed.

There should be no room for error when it comes to specs quoted directly from the manufacturer on their official site, especially for a watch costing around $4,000. With that said, compared to watches with similar functionality, the ST1961 seems to be the most affordable offering yet. Perhaps it will gain even more recognition if they decide to sell to other brands rather than keep it exclusively for their own Sea-Gull branded watches. We shall see…

Additional Resources:

• More Seagull mentions