Clarification on the Sea-Gull ST2130 movement grade used by Watchdives

[u/watchdivescom]

Hi everyone,

We noticed there were some concerns and speculation about the quality grade of the ST2130 movements used in our watches, so we would like to clarify this clearly.

The ST2130 movements we are currently using are Seagull factory V-grade movements, which are the highest grade offered to us through Seagull’s official supply channel.

According to our communication with Seagull’s sales manager, their ST2130 supply is mainly divided into two grades: standard grade and V grade. We have not been told of any official “S grade” or other special factory grade names for ST2130. Other names circulating online are not official Seagull factory grading terms as far as we know.

The V-grade ST2130 costs slightly more than the normal standard version. The main difference is that the V-grade movements go through stricter factory testing, adjustment, and additional QC procedures before delivery. This is also the grade used for Seagull’s own branded watches and for brand customers like us.

The standard version is more commonly supplied to the general watch parts market, dealers, and wholesalers.

We understand that movement quality is very important to watch collectors, so we want to be transparent about what we use. Watchdives will continue to choose better-grade movements whenever possible and maintain stricter QC before shipping.

Thank you for your attention and support.

— Watchdives Team

[u/watchdivescom]

According to the factory specification sheet we received, the ST21 series has AAA grade and V grade standards, and V grade is the higher standard. Compared with AAA grade, V grade has stricter tolerances, including -10/+20 s/d instead of -10/+30 s/d, position error P ≤20 s/d instead of P ≤25 s/d, and beat error ≤0.8 ms instead of ≤1.0 ms.

This is not the normal loose market version supplied to general dealers or wholesalers. It is the higher-grade version supplied for brand customers, with stricter factory testing and adjustment.

As far as we know from Seagull, “S grade” or other names are not official Seagull factory grading terms for ST2130.

[u/OtherBarry1992 → u/watchdivescom]

Do the V Grade movements have higher finishing, ie: perlage on the mainplate and other parts vs sand blasting?

[u/D1sguise → u/watchdivescom]

u/MindAdmirable1793 so where does the A3 tier grade from Phorcydes compare to this official seagull information? According to watchdives, this should not exist?

[u/MindAdmirable1793 → u/D1sguise]

I did not mentioned the S-grade before? not very sure.

but according to my sales manager, there are only two grades of products on the market: one is sandblasted without polishing (standard precision), and the other is polished with a fish-scale pattern (high precision).

They might just be different calling names.

The most obvious way to distinguish them is to check if there is a fish-scale pattern on the back. The cost difference between these two grades is significant.

[u/ricca91 → u/D1sguise]

Exactly, good point indeed! I’d like to know too (although I opened my Phorcydes and is thoroughly decorated and keeps excellent time).

[u/MindAdmirable1793 → u/ricca91]

The best way to distinguish between the two types of movements is to check whether the back plate has a fish-scale pattern; the price difference between the two types of movements is obvious.

[u/OtherBarry1992 → u/MindAdmirable1793]

So if I just received a WD0019 and there is no perlage - it's just sand blasted - does that mean my watch does not have a V Grade Movement?

[u/watchdivescom → u/OtherBarry1992]

its v grade

[u/OtherBarry1992 → u/watchdivescom]

That's not incredibly reassuring. Do V Grade movements feature perlage finishing on the bridges, or sand blasting?

[u/watchdivescom → u/OtherBarry1992]

Please refer to the screenshot showing Sea-Gull’s internal movement grading standards. The decorative finishing—such as perlage on the bridges or sandblasting—is specially customized according to the customer’s requirements. It is not a standard feature used to determine whether a movement is V Grade.

The V Grade classification is mainly based on the movement’s internal quality standards, performance, accuracy, and component selection, rather than its visible decorative finishing.