Seiko Marinemaster 300 Review - The Best Japanese Dive Watch? | Armand The Watch Guy 

One thing I love about this watch is that it has its own identity. It's nothing like a sub or Seamaster. It is big, bold yet elegant.

It is simply a masterpiece! Of all my watches, it remains my favorite.

That has got to be the most complete description and review. Thank you

Image quality of the video is excellent. You really get an idea of how the watch looks from all angles and can appreciate the polishing and brushing. All topped off by a no nonsense review. Nice one Armand!

The Japanese Rolex Submariner! Am hardcore Rolex Sport watches but always loved this model Seiko diver. Picked up a MM300 recently and found the price had really increased since last year. Still well worth it. Rich history, great value, fit finish and just a well executed Diver. Main gripes. Bracelets a bit sketchy and it should have sapphire at this price point. Like to see a Ceramic bezel but the polished lacquered bezel looks fine. Mine is a consistent + 7 a day. I found it wears much smaller than any 44mm watches out there. The bezel is actually closer to 42mm and the dial is smaller in proportion. It’s not small by any means but I can wear it just fine on my 7” wrist where most 43-44mm I cannot. Thickness of the MM300 being the main issue, it does sit high on the wrist but still manageable. The word chunky comes to mind. Those sitting on the fence you might want to move on one before the supply dries up.

I have this exact model. I actually sold one and re-bought another one not long after I sold it. I would sell all my other watches before I ever sold this one. Great video.

I own several watches, including this model, also a rolex James Cameron. The MM 300 is by far my favourite watch a the one I wear the most. Love it. I never get tired of looking at it. Fantastic watch.

Thank you for this seminal review of a wonderful diver watch, a model that really stands out on its own, tall and defiant, in an overpopulated segment. Love it.

My grail, amazing review and great camera work...Thanks!

Great review! I just got the mm300 a couple of days ago. Even though your video shows the watch from different angles and quality is great, I think that you need to see it live to appreciate how stunning the watch is. I own a couple of Doxa watches and was always sceptical when I read comments about mm300 and how amazing it is. Now I finally decided to get it when it was discontinued. I was really surprised of the quality and overall feel, one of my favourite watches! But yea, really enjoy your videos, keep up the great work!!

I agree... It's one of the most impressive watches I've ever seen.. It might be my favorite watch of all time. It's simply a masterpiece;)

Lovely watch,first class review as always! Cheers 👍👍

This is a truly amazing watch. It seems like Swiss manufacturers have something to learn from it. Thanks for your review!

Brilliant presentation and description of the watch. Thank you!

Man I've been watching this watch for a while , having just purchased my first grand Seiko quartz 40 m . I can now start saving up for this bad boy....great review as usual

Great review as always Armand ....great knowledge and thank you.

Very informative video. Great review.

Please do not forget the wrist shot, especially when you are reviewing a tall watch. It looks fantastic with a nato but it also concerns me that nato adds to the height. A beautiful looking watch; its design is just so unique and unforgettable. Cheers~

Awesome review Armand! Have this grail in mypossession as I just recently picked up a BNIB-never been used SBDX017!

Late to watch this. Awesome review. Thank you for the effort.

Beautiful opening!

I would love to own one of these watches to go with my collection ! Thank you for the review good job!

Great review of an amazing watch!

Best intro into a Seiko watch ever.

Brilliant reviews sir!

Fantastic review. Thank you.

great watch and great review

Brilliant review (as usual)! Have you seen (handled/experienced) the new Seiko 300 diver from the Prospex line of watches and how does this new timepiece compare to the older and now discontinued Marinemaster?

That opening was beautiful.

I’ve just purchased the MM300 (017 Version) 1year after watching your review.I know you’re selling or sold your one Armand, but still a fantastic discontinued piece.Even better in the flesh. Probably a classic,if not already.

I just got the SLA019 mainly because the SBDX got discontinued and because it looks awesome. If I had a choice given the price i would have got your model but the green really is nice as well. So far I love it!

Armand, the little gap between the bezel and the case between the lugs is to fit in a case knife or tool to remove the bezel.

Love the intro!

Outstanding video and watch. I'm enamored with my SBDX017. Armand, I'm wondering if you could tell me/us about your lighting setup for this video. It looks great and I'd love to do something similar for my videos. Thanks!

Great video quality!

Armand, I consider you the best RU-vid watch commentator right now! Keep it up! "As a result" count = 1 :-o

Great review!

Thank you for sharing this beautiful watch Armand. One would hope that Seiko would do both release the cheaper version and a more expensive version (though maybe not $5000) with sapphire and ceramic. Fantastic video, thank you :)

This one is in the class of its own. There's no other badass like this.

Just received my Green Forest. This watch has the ceramic bezel and sapphire crystal. It is truly game changing. It is simply magnificent and is a real piece of art as much as it is functional.

The watch case is almost worth the price alone - is the finish too good for a dive watch? Of course, it’s a good dress watch. Good review.

Is it common to hear the sound of the road or when you shake the watch? I don’t remember hearing it when I first purchased my watch.

so far the best review for MM300

I listened to the opening Japanese music few times 😊

Where can I buy the green straps? Let me know ASAP thanks

Nice watch. For a Edc though I prefer my Sea monster with green NATO strap. Keep up the good vids.

Lovely review of the Seiko MM 300m 8L35. Just today I was really lucky 🍀 to find a 2018 Basel released SLA019J1 with the cedar green sunray dial and newest green ceramic bezel inlay. After seeing the high praise you lavished on the Marine Master 300 I decided to go-ahead and buy this 1968 pieces Ltd Edition Green version SLA019J1. Regards Cyrus

Don’t often hear “slim profile” in an mm300 review. Nice vid 🌊

It seems that there are so many haters of this watch. I guess, they really wanted it but could not be able to get it as it is discontinued and the available in the market is skyrocketing in prices.

Could you kindly share what Nato strap Brand that is?

Nice watch. Congratulations.

Wonderful watch and great in-depth review. Only missing thing was a wrist shot. If you could choose between the new ceramic bezel version and the version you have, which one would you go for?

Beautiful watch.. people complains about the height of the piece.. but they forget that this is a tool watch and is not for desk diving

A stunning Japanese classic watch absolutely love it attractive and seductive looking time piece would love to have one of them in my collection one day Armand it would be really cool if you could organise a meet you with fellow watch guys kind regards as always Terry

Love that NATO. What is the brand or maker of the band?

Is the strap silicone? I thought it’s rubber but I could well be wrong.

Want tudor rolex omega no more.. I want this!

A great review of a truly fantastic watch. What a shame neither the watch (in true Marinemaster form), nor this channel continue in 2022. Many in the community miss Armand's insightful and enthusiastic reviews and many miss the iconic 'Marinemaster' branding of this brilliant diver.

I've wanted this watch for some time but it has been out of my price range. Too many other expenses needing taken care of. Since its discontinuation the Marinemaster 017 has gone up considerably in price. I'd love to own this watch but can no longer justify buying it. I stumbled on information, however, that Seiko will soon be offering revamped versions of the 017: the SLA02J1 in black, the SLA023J1 in blue, and a rather unique looking version the SLA027. I'm anxious to know the release date.

I’m in a Seiko monster phase at the moment!

I think it is also great that Seiko offers the Sumo if you want something similar to this watch but cant manage the price.

The 8L35 is based on the now defunct first gen 9S (ie 9S55) which had power reserve of 50 hours beating at 28800 bph. Current generation of 28800bph 9S is the 9S65 which has 72 hours power reserve. It is correct to say 8L35 is a unregulated GS movement with less decoration compared to 9S calibre.

That's a great watch. There's no doubt Seiko lume is one of the best in the market. Currently, THE best of any watch brands I currently own. I had a SBBN033 Tuna and I believe it shares the latest Lumibrite formula as your MM300. As you noted, I can also vouch that the lume is super reactive and the dial is basically legible at any time of the day or night even with minimal charge time. The Lumibrite formula practically eliminates any perceived advantage tritium tubes might have being they are easily well energized and visible basically nearly all the time. My CW C60 Tridents also lasts quite long, but they are not as bright, but then again mine have the faux aged radium look so understandably not a clear bright glow as an "untreated" lume application. Thanks for clarifying the movement. I think, for me, it's been questionable whether it was a dumbed down GS movement or a really high end Seiko movement. It's a hefty watch, but not overly, as most large cased Seiko's can magically pull off. And, the proportions are appropriate for such a tool dive watch.

I remember watching Armand in a video where he told his audience that he was going to sell his MM300. I also sold mine around the same time abs I have to say it’s probably the worst sellers remorse I ever experienced. Luckily managed to get a great example recently. Wonder if Armand also got sellers remorse from selling his MM?

Have a Limited edition seiko Turtle 🐢 with the 8L35 movement more accurate than my Omega Seamaster 300M This Seiko Marine Master is very tempting 🤔 buy selling the Omega Seamaster &getting one Brilliant review

I miss the Watch Chronicler!

You went back to "over and out"? Still a great video though!

what's the name of the song? that's beautiful

The non limited edition Marine Master 300 is coming out Black version is the SLA021J1 and the blue version is the SLA023J1

pre loved orient saturation diver os300 is it's equal for half the money. love the mm300 but specialist servicing puts me off.

How about - crown thread being welded into the case - so it WILL eventually werr off - 700usd for the case...

I don't think it is necessary for a tool watch to have a high beat movement imho a 21,600bph movement would be sufficient but Seiko should design a better quality 21,600bph movement for it than they currently produce.

Brilliant review. Love mine.

Great video however I'm still unsure why Seiko gets a pass as it pertains to producing watches that are too large. I've owned Seiko timepieces and unfortunately they don't defy physics... it wears like any other 44mm watch that's extremely tall. Too bad because it's a nice timepiece😪

I find it incredibly odd that they've gone to the trouble of designing and producing a monocoque case to eliminate one possible point of failure at the caseback (which is not the most likely point of failure), and then they've employed a crown/tube assembly which has only one small gasket around the stem, just like an SKX007.

Weird times, my 450 euro prospex seiko diver in 2023 has sapphire, glad they finally accepted people want sapphire.

Just get the Seiko SBDC051 and save yourself $1500. But if you want to spend $2,000, then get a Sinn U1 made of German submarine type 212 steel.

Beautiful addition I slightly enviously have to admit, congratulations. But nevertheless I always get the feeling of many diving pieces being the SUVs of the watch industry. Vastly overengineered penile extensions that derive their existence from an assumed sportyness. I only wait for artificial patina and a few salt crystals on the dial to prove the heavy use... :) Not that i am not a fan of overengineering, but a He valve to splash around with the kids in the pool, well...?

Prices are increasing...sadly 🙄

I'm really so beyond sick of seeing companies promote dive watches using features like "helium escape valves" and "saturation use" features. Seriously, there are LESS THAN 400 ACTUAL "Saturation" Divers in the U.S. alone, and less than 2000 registered working for companies and military services around the world. Basically, YOU have ZERO need to worry about ANY amount of Helium gas "ruining" your watch or popping off the glass. Unless YOU are in the process of becoming a real-life saturation diver, YOU will NEVER need a watch with an escape valve nor a monoblock case. And seriously, ANY dive watch can be used for saturation diving and be just fine upon decompression so long as you remember to unscrew the bezel during the process. If you're a real SCUBA diver, any dive-rated watch will do just fine.

Its not really a tool watch at £2000 pounds its more a jewellery piece with some interesting design. Who would in their right mind risk going deep diving with it when you can get 1000m diving watches now days for well under £400.

Seiko discontinued these, I believe...hold onto them!

Over and out? Oops 😉

I honestly never understood the charm of this piece. It's too thick and impractical for me. Water resistance? Yeah, it's good, but how many owners would even surpass a 10 atm pressure? A safe ballpark estimate would be less than 1%. Solid caseback rather adds problems upon service, as you are pretty much stuck with seiko's service, which isn't very good even for GS (I'm judging based on a number of threads on WUS). 8l35? Well its not regulated much, anecdotal evidence about high accuracy is irrelevant, as there are as many comments about same level of accuracy for top-grade ETA2824, which is found in much cheaper divers. I think the entire market for this watch is people who wish to buy a GS diver, but can't afford it. Honestly, is there a person in the world that would choose this over a SBDX019 or a GS diver if given enough money?

Orient Saturation 300 isn't far off and much cheaper.

I useluly hate your intro, and always try to avoid it, but this one is very nice. I wish they'd try a little harder to make it less "Swiss".

MM300 is great but also topheavy unfortunately

So having showers with this watch shouldn't be problematic???

Your wrist will get buffer just wearing it.

Please introduce us the watch with the original strap before putting on a different strap consumers need to have an idea of what the watch looks out of the box. Thank you.

The bracelet is a total piece of crap, I hate the pin and collar system, there are some microbrand watches with a much better screwed bracelets for $500. The clasp is so thick that it is unusable as a desk diver, putting is on a nato is a good choice.

Meh. Seems way too tall. Proportions don’t look right to me. I bet it wears very top-heavy. Looks like a Japanese hockey puck. 🤪