Beating inside is the 8L35B, which is the same movement as the SBDX017 with the MEMS technology. It is an undecorated version of the Grand Seiko 9S55 with less movement decoration and no regulation. So while the 9S55 has higher accuracy, the listed accuracy for the 8L35B is +15/-10 seconds a day.
During the brief period I have owned the watch it has been consistently about 3.8 seconds fast a day, definitely within COSC specs. As previously mentioned MEMS helps the watch maintain isochronism so when the watch is low in power, the accuracy does not become erratic. The movement also has the magic level system common in Seiko/Grand Seiko watches, which increases the efficiency of the rotor, so even sitting in front of a desk all day wearing the watch, it will easily charge to full power with no issue. This is needed as the power reserve Also known as Power Reserve. A watch's power reserve refers to the amount of time a mechanical watch can run without being wound. The power reserve of a mechanical watch can vary depending on the size of the mainspring, the efficiency of the gear train, and the rate at which the mainspring releases energy. If a watch has a Power Reserve 'complication' it simply means that the status of the power reserve can be seen on the watch itself (either on the dial or movement side of the watch).
[Learn More] on the 8L35B is 50 hours, while it is still a full 2 days, it is a big lagging when many movements these days run for 3 days/72 hours easily.
Great write-up Jeff! Aways enjoy your hands-on real talk. Such a great watch and sensible alternative to the great (and expensive) LX. Also, how big is the BP if it dwarfs the MM? 😅👍
BP is 46.2mm vs. SLA 44.3mm, but next to each other, feels there is more than 2mm doesn’t it? 🙂
Makes it look like a 40mm watch to be honest! 🙂
Hehe, it wears like a 40mm watch too 😉 Was surprised you didn’t use the lume shot for illustration though
Great timing for this article. I’ve got a SLA023 en route to me from Japan as we speak. I’ve ordered the CrafterBlue fitted rubber strap that works with the MM300 OEM adjustable strap. I went with brown rubber as I feel that plays with the blue of the dial nicely. This will be my first ever Marine Master and I am extremely excited. Cannot wait for it to arrive. Great write-up.
Let me know how you like it on the crafter blue, I was tempted to go for the orange but ended up with the Uncle Seiko orange strap for now, I wish they had a blue strap for the SLA023!
I’ll absolutely report back on the CrafterBlue once the strap (and the watch for that matter) arrive. I was disappointed that they don’t offer a fitted Blue strap for the SLA023. Maybe if we bug them enough, they’ll make it happen. For now, I’m really hoping the brown rubber will work with the blue dial and bezel. If you want, you can keep an eye on my instagram as I tend to post all of my watch’s there (probably far too often). I’ve always really been interested in the MM300, but never enough to actually make the purchase happen. This colorway of the 023 had me from the moment I saw it. My Grand Seiko “Whirlpool” SBGH267 also uses a blue dial and gold second hand, so naturally if I was going to add a MM300 along side it, it had to be the 023.
My instagram username is @canuckrs
Congrats with the new watch incoming! I’m confident the brown strap will work very well with the blue dial. Brown strap and blue dial rarely fails to impress 🙂
Hello, can you tell which brown strap is shown in the pictures? Looks awsome!!