Watch Review: DELTAt UMI


Company: DELTAt


Model: UMI


Japan Time Module (Seiko) Automatic Movement Cal. NH35A

Lumed Hour, Minute, and Second hand
Hacking seconds

44mm diameter
15mm thick
103g without straps
316L Stainless Steel

Sapphire Crystal with anti-reflection coating
Water Resistant
300m/990ft (30ATM) Water Resistant



From a design standpoint there are many things that make a dive watch something special for me. So special in fact, they are one of my personal favorite style of watches. A detail that just adds to the coolness factor of a dive watch is that most can withstand going into the pressure filled depths of the ocean. There is something that is just so rugged and badass about a dive watch. Lovers of dive watches know what I am talking about. If you don’t know what I am talking about hopefully today I can help explain it to you because we will be taking a look at the DELTAt Umi.


This is their latest addition to their growing collection of watches. I had some good experiences with 2 watches already from their collection so I was excited to see what the Umi was all about. From first glance the Umi screams dive watch. It’s hearty 45mm x 15mm 316L stainless steel case feels and looks like it can handle some abuse. The Umi’s head alone weighs in at 103g. The majority of the case has a brushed finish which is my preferred finishing on a dive watch. I’m not entirely into polished finished cases on a dive watch as it seems out of character. I do wear my dive watches to desk dive, but I also use them out in the field-diving, climbing, hiking, etc.. So it’s important to me that a watch can handle what I put it through and that it won’t skin it’s knee at the first sight of an adventure. Polished finishes in my experience tend to show every spec. Anyone who wears a watch during these type of adventures doesn’t want to worry about babying their watch. The Umi can handle up to 300m of water resistance which means it can handle all areas of recreational use like the shower, pools and can handle some pretty serious diving use as well.


Looking at the Umi it was hard for me to ignore the unique bezel so I’ll start there. The angle at which the edges to grip the bezel are cut makes for a good looking change of pace bezel. It almost gives it a buzz saw blade appearance giving the Umi a no nonsense wrist appearance. The bezel is very easy to grip and rotate with 120 clicks of buttery smooth goodness. There is absolutely no play whatsoever with this bezel. The bezel is also clear of any numeral/markings except for the lumed faux pearl above the 12 o’clock position.


The screw down crown is well protected by some very cool, large, squared crown guards. The crown looks good as well thanks in part to the engraved DELTAt logo. Looks aren’t everything though, function is more important but no worries here, the crown functions perfectly. Both screwing/unscrewing and with setting the time/date are done with smooth ease. Gripping this bad boy is equally easy thanks to the gear edges that help eliminate your fingers from slipping off. For those of you who like to be peeping Toms into your watch movements you will be pleased to see that the Umi has a sapphire crystal exhibition case back. You get to see the Seiko NH35A with it’s 24 jewels and beating at 21,600 vibrations per hour. The NH35A has a 41 hour power reserve and its standard accuracy rate of +10~30 seconds per day rate. During my experience with the Umi it was keeping +7 seconds per day.


Telling time on the Umi is not only easy, but it is also a thing of simplistic beauty. The backdrop for this dial starts to paint the picture of a something that’s easy on the eyes. The matte black dial is that perfect canvas which serves two purposes, one it looks good and two it cuts glare down considerably. The polished hands are easy to see in well lit environments thanks to the pure white inside coating which is equally as easy to see in dark environments thanks to the coatings of lume. The applied indices received the same quality treatment, bordered in the same polished metal with white inside, coated in lume. Coming together in beautiful harmony. The second hand has a lumed circle at the end that finishes the hands quite nicely.


With no numerals on the dial, DELTAt has to make the dial interesting in another way. Of course the hands help this cause and the applied lumed/polished indices do as well, but they went a step beyond here. At the 12 o’clock position is a larger triangle and at 6 & 9 there are rectangles which give some good focal points on this dial. At the 3 o’clock position you will find the date window which features a white wheel with black printed numerals. There is some text on the dial as well, which is located under the 12 o’clock position and above the 6 o’clock. I really like that the word DELTA is in white and the ‘t’ is in red, a nice touch of color goes a long way here. Bordering in all of the dial’s goodness is a thin white minutes/seconds track that completes the Umi dial brilliantly.


The Umi comes with a wide variety of straps which is really awesome because each one if completely different. You get a
22mm width rubber strap, a nylon velcro straps, And a paracord strap with multi-tools buckle. The paracord strap is so cool as I have never really seen a strap like this. It features a whistle, a saw, a compass, all tools thank are pretty useful when out in the field either deep in the woods or out in the water.

The rubber strap is the more simplistic strap of the trio. It has raised square texturing throughout both halves and features a signed, brushed finished tang buckle. Finally, the Velcro strap is pretty awesome. It reminds me of a pilot watch I reviewed awhile back that featured the same style Velcro strap. The difference is the thickness of the DELTAt strap and the wide buckle that looks badass. The orange stitch detailing on this strap gives it a completed finish that looks fantastic.


There are a lot of options out there for people looking for a microbrand diver. And having options is a great thing, trying to narrow down those options is where the challenge comes in. That’s why I am here to help offer my two cents to hopefully aid in the narrowing down process. The Umi is a nice blend of classic styling with modern day influences scattered about it. The large thick lugs and crown guards give the Umi a rugged, no nonsense modern look, teamed up with the large brushed bezel makes for a tough looking case. The classic dial is simple and well executed.


What DELTAt has done to set the bar higher is they included extra straps. Yes other companies have done this as well, but I’ve never seen such a wide variety of styles included in a watch kit before that was straight from the manufacturer. Of course you can find such offerings on the secondary market, but having this kind of offering from the company itself makes this very special. The waterproof case the Umi comes in is cool as well, which can be used as a small travel tool box which comes in quite handy because of its waterproofness and because it easily fits in the glove box or your back back. Pretty damn handy if you ask me.


I would definitely recommend the Umi to someone looking for a good experience with a microbrand diver. There is enough here that makes the Umi a good value and a solid offering. Check out their website for all the variations of the Umi.


I want to personally thank DELTAt for allowing me the honor to review the Umi.


This review is dedicated to Brice and his family. My thoughts and prayers are with you now and forever.



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