Welcome to the second semifinal match of Fratello’s Seiko World Cup. Five Seiko divers have been eliminated so far, while three others remain to face their next opponent. Today, G2’s SBBN011 “Darth Tuna” battles RJ’s SBDX001 “MM300.” Both watches have iconic status, so we expect it to be a tough fight. Will the MM300 design prevail over that of the hockey puck, or will the Tuna’s 1000m depth rating leave the SBDX001 in the shade? We can’t say for sure, but one thing is certain: only one watch will emerge victorious and move on to the final round.

In their first bouts, we saw that both the Darth Tuna and the MM300 have a huge supporter base. Now is the time to find out which is the most loyal. Let’s see if either G2 or RJ will be able to mobilize more souls and make the difference in votes big enough to take the win. Get ready for another round, and cast your vote at the end. Don’t forget to defend your pick in the comments below.

Gerard: SBBN011 “Darth Tuna”

In sports, it’s not always about beauty. Knowledge and technical agility are often decisive. Today’s contenders technically have more in common than you may expect; they’re both saturation-dive-ready watches and made using a monobloc case construction. However, regarding functionality, the MM300 must acknowledge that the Darth Tuna is superior. Here, form follows function. The round tuna-can shape (from which the “Tuna” earned its nickname) and the circular ceramic shroud bring many advantages.

Tuna vs. MM300

Functionality of the Seiko Tuna’s shroud

The most important thing is that the shroud protects the watch. Being ceramic, it also does not scratch easily, so even when used for actual diving, the watch remains looking good. However, simultaneously, the shroud protects the diver’s bezel from being rotated unintentionally when the watch is hit. Only a relatively small part of the bezel’s rim is exposed  Of course, the bezel is unidirectional, but even in that one direction, it’s better to not have it rotated unintentionally.

SBBN011 bezel

Unique looks

The third major point for the shroud is that it determines the watch’s looks. The Tuna became famous because of its design. Unmistakable and unique, there’s no watch like it. Originality is a great asset in the watch industry. We see so many watches derived from or resembling a certain design. If nothing else, the Tuna is a unique watch design in and of itself, which means you either like it or you don’t. Regardless, you certainly won’t mistake it for any other watch. A Seiko Tuna is not everyone’s friend, but I hope it has enough friends here to win this battle.

Seiko Tuna

The Darth Tuna is comfortable to wear

With a case diameter of almost 50mm, most people think a Tuna won’t fit their wrist. But as I already explained in this article, that’s not true. Regular watches have a lug-to-lug distance between 42 and 52mm. These will comfortably fit wrists with a circumference between 17 and 20cm. Monocoque Seiko Tunas do not have lugs, meaning there’s no actual lug-to-lug distance. With the Tuna, it’s the distance between the strap ends that matters. This dimension is around only 35mm, and that’s why the monocoque Seiko Tuna models wear so well, even with a 50mm diameter.


I don’t want to win on specs, but they matter

I just discussed the importance of the Darth Tuna’s measurements. But what about the depth rating? The SBBN011 is ready to conquer 1,000 meters of water, while the MM300 can handle 300 meters. Both are probably over-specced, although saturation dives, of which both watches are capable, might go as deep as 300 meters. As the Divers Alert Network states, “Today, most saturation diving is conducted between 65 feet and 1,000 feet.” It’s not entirely relevant here, but it’s interesting to learn that “decompression from these depths takes approximately one day per 100 feet of seawater plus a day.” Hey, that’s probably why these dive watches have a date function.

Darth Tuna

Why should the SBBN011 win?

Why should you vote for the SBBN011 Darth Tuna over the SBDX001 MM300? You probably shouldn’t. The Marinemaster 300 is too hard to beat; for many, it’s the endgame Seiko diver’s watch. Nothing beats the MM300. But hey, if I have to, I will go down fighting. The Darth Tuna’s design is distinctive and inspired by its function. This made the SBBN011 what it is — a dedicated diver’s watch. And that’s what we’re voting for here, isn’t it? At this point, I would also like to draw your attention to the fact that there was no need to technically change this watch in over 20 years. That’s quite difficult to ignore.

RJ: Marinemaster 300 SBDX001

This is an interesting battle! Both watches belong to the Marinemaster line, yet they are totally different in design. I used to own the Grandfather Tuna ref. 6159-7010, a very cool watch that could compete with the PloProf and Sea-Dweller when it came out in the 1970s. Gerard’s Darth Tuna is similar in design, but it relies on a quartz movement. Now, I don’t mind a quartz movement, and I have several battery-powered watches. However, when compared to a Grand Seiko 9S55-based mechanical movement, it’s an easy choice for me.

After a few years of ownership, I sold my Seiko Tuna 6159-7010 because I found it uncomfortable to wear. Sure, there are no lugs, but a 50mm diameter wears like a hockey puck on the wrist. I can see that this can be cool sometimes, and it’s often a conversation starter, but as soon as I find myself taking off a watch because it’s simply uncomfortable, I disconnect with it. That said, I agree with Gerard that the Tuna remains a cool-looking watch.

A wearable serious diver

Admittedly, the Marinemaster 300 (I did a rundown of its specs here) that I selected for this competition might not have the thin case of a Rolex Submariner or the finesse of a Blancpain Fifty Fathoms. But it does the job of being a professional diver’s watch and should be considered more of a tool watch than a luxury watch that can also be used in the water. The Marinemaster 300 SBDX001 does look nice on the wrist regardless. Seiko ensures the watch has the famous Zaratsu polishing on the case sides and some proper satin finishing on the lugs. But the best part about this watch is that it’s incredibly wearable, even if the 44mm case diameter suggests otherwise.

Seiko ruined a good game

Although the SBDX001 remains my favorite Marinemaster, specs-wise, its successor (SBDX017) was even better. Afterward, Seiko removed “Marinemaster” from the dial and started to use the Prospex logo instead. Not only that, but Seiko also felt the necessity to increase the price to just over €3,000. It’s still a fair price looking at the value of the watch, but the SBDX001 was really a steal at the time.

Seiko Marinemaster SBDX001

It’s a versatile watch

Whereas the Darth Tuna is difficult to dress up or down, the MM300 is more versatile. I remember Gerard wearing his Marinemaster 300 (SBDX017) on a beautiful leather strap, but it’s also nice to combine with a rubber strap like the Tropic-style one in the picture above. Originally, it came with a steel bracelet as well as a rubber Seiko strap. I didn’t find the latter to be very comfortable, and it was a bit too long, even for my fairly large wrist.

Why the SBDX001 should win

To me, the Marinemaster 300 SBDX001 is (or was) a watch that stands for everything that Seiko is about. It is incredibly reliable, over-engineered, and fairly priced, and all of that is combined with a classic diver design from 1968. Is it the best watch in Seiko’s range? No. It has neither a sapphire crystal nor a sapphire bezel insert, and the extension clasp of the bracelet is cheaply constructed. If you can live with these shortcomings, you have yourself a wonderful diver’s watch that can also be worn outside the water. If you come across one of these watches in the pre-owned market for anywhere below €2,000, you should go for it and thank me later.

Cast your vote!

Now it’s the moment of truth! Which watch deserves your all-important vote? Is it the uniquely designed and ever-capable SBBN011 Darth Tuna or the more classically styled and versatile SBDX001 MM300? Select your victor below, and chime in with a comment about why you chose it as well!

Seiko World Cup: G2's SBBN011 vs. RJ's SBDX001