8×40 Mariner



8×40 Mariner

(14 customer reviews)


Oberwerk Mariner binoculars offer excellent image quality at a moderate price. In fact, SPACE.COM recently reviewed the 8×40 Mariner and named it Editor’s Choice! These extra-rugged waterproof binoculars are ideal for hunting, surveillance, astronomy, and of course nautical applications.

The 8.4° Mariner has one of the widest field of views available from an 8x binocular. All air-to-glass surfaces are fully broadband multi-coated to decrease light loss due to scattering and reflections, a feature normally found only on binoculars with much higher price tags. The Oberwerk Mariner features heavy-duty construction, BAK4 prisms, precise center-focuser, right ocular diopter adjustment, twist-up eyecups, brass 1/4-20 tripod adapter threading, extra-rugged nylon padded carrying case, caps, and neck strap.

Recommended mounts-
Oberwerk 2000 Monopod
Oberwerk 3000 Tripod

Additional information

Weight 5 lbs
Dimensions 13 × 11 × 7 in


Eye Relief

10.0mm (usable)

Exit Pupil


IPD Range


Minimum Focus


Product Weight

2.2 lbs.

Product Dimensions

L=5", W=7", H=2.5"

14 reviews for 8×40 Mariner

  1. Aidan Gribbin

    Having deliberated about buying another pair of binoculars for a month, i was finally inspired to take a chance on a pair of 8x40s made by Oberwerk. At one time the admission that they were “made in china” might have put me off (do yourself a favour and visit the homepage of the highly impressive Holger Merlitz, scroll down to the bottom of his homepage and click on “review-current Chinese 8×40 binoculars”) but the quality of binocular manufacture in china has soared and these delightfully chunky Oberwerk mariners are testament to that fact.
    They arrived very well packaged, and once in my hands, the weight and robust feel left me in no doubt that, short of throwing them under the wheels of a passing truck, these binoculars are going to last forever. The case is equally “up to the job” and the rubberised lens covers fit very snugly and have a much nicer feel than the conventional hard plastic type. Comparing them to my fairly respectable Japanese 10x50s dating back to the 1980s, the clarity of the mariners is far superior with no appreciable edge distortion (unlike my 10x50s), elasticity (3D effect) is wonderful and collimation is as far as i can determine spot-on, though i will have to wait for a “starry” night to really satisfy myself on that one; however, Oberwerk being specialists in the astronomical binocular department i have no doubt i will be more than happy perusing the wider heavens with these impressive optics. The controls (IDP adjustment, focusing and dioptre adjust) are all heavily dampened (i.e. they require considerable effort and are slow to move) which means that once you have adjusted them to suit both your individual requirements and found focus on your “target”, they are going to remain that way unless handled very roughly.
    There is tripod socket but don’t make the mistake i made and assume it will simply fit onto a standard tripod; you need the special adapter and i feel a little remorse at not having ordered one with the mariners; having said that, at 8 times magnification with the wide field of view that the 8x40s have, handshake is rarely going to be an issue, but if ever you envisage repeatedly returning to your binoculars whilst making notes about, or sketching something you have fixed your focus on, then a tripod adapter will make your task a lot easier. To conclude- if you are considering a binocular purchase, do your homework with regard to the magnification you require, ask yourself if weight is an issue; the appropriately heavy duty construction makes the mariners comparatively heavy and whereas this is not really an issue if you are travelling with them alone, add a tripod, camera, packed lunch, rain gear, portable toilet (just joking) etc, and weight will very soon become an issue. These binoculars are excellent value for money, and i for one am very pleased with my purchase from Oberwerk in every respect.

    • Aidan Gribbin

      I expanded at length in my original review and so will try to be more concise with my update.
      Firstly, I refer back to my “having to wait for a starry night” for confirmation of the precision of the collimation; I can confirm it was and still is, flawless-pinpoint accuracy and star-gazing as a result is a joy! I still love these binoculars and whilst I would dearly love a pair of the more powerful Oberwerk binoculars for star-gazing, the wide field of view of the 8x40s is excellent for general gazing; also superb for bird-watching and “glassing” in general. In the interim years, while out for a cliff-top walk, I bumped into a dedicated bird-watcher who had a very expensive pair of bins around his neck (in the region of 5-10 times more expensive than my mariners) and with great excitement I asked if I could test them out; I have to say I was not impressed; they were in no way superior to my 8x40s). Looking through a good pair of binoculars at anything is always a joy to me and the mariners thrill me every time. I will reiterate that the mariners weight, while testament to their robust quality, is perhaps not the best choice for a long days nature walk; I have a lighter pair of Nikons for that, but optically I much prefer my mariners.

  2. Kevin Criss

    This my second Oberwerk purchase review to date. The other week I wrote a 5-Star review of the 10X60 binoculars I recently purchased and was so impressed by the overall quality of those binoculars I decided to get a pair of 8X40 as well. So this is my 2nd Oberwerk binocular review and specifically for the 8X40 Mariner binoculars that you will find below.

    So I’m the guy in the 10X60 review who claims not to be an optics expert in one of those other two reviews. But I do have (5) pairs of binoculars all of which are MIL SPEC or a military style binoculars (BAK4 prisms) and none of those have zoom capabilities whatsoever. In that other review I forgot to mention I also have a pair of Zhumell Tachyon 25x100mm Astronomy Binoculars that I picked up recently too and by the way I absolutely love those Zhumell binoculars, but I came back to Oberwerk for a 2nd purchase because they are just that good. Didn’t want to lose out on some kind of a sell out event not knowing the extent of manufacturer’s inventories or what might still be in their production pipelines.

    The 8X40s still have a bottom lens cap system best left in the camera bag and not taken into the field otherwise the overall fit and finish of the binoculars is outstanding. These will be my every day binoculars. I will be keeping these on hand or in the truck. I may even get a Swarovski harness for these as I intend to use them a lot and don’t yet see Oberwerk offering harnesses yet.

    O.K. so I brought up binocular harnesses in a product review on what some might consider a compact pair of binoculars so let’s talk about image stabilization. With the 8X40s you don’t need it. In the old days image stabilization meant using a tripod and/or today it might also mean some kind of built in electronically stabilized imagery too. Its not necessary in a 8X40s or 7X50 magnification and so I don’t even think about stabilization until I switch up to 10X and above magnifications. Harnesses are cool and are more about being on the go than about stabilization. I’m taking these 8X40s with me everywhere I go.

    I don’t own a pair of fashionable SPORT type (roof prism) binoculars I prefer a military style (with bak4 prisms). Sport type binoculars are lighter in weight usually than a comparable magnification in a military style of binoculars but the field of few is usually bigger with a Mil Spec style.

    The see through experience on these 8X40s is the best of my entire collection. Buy the 8X40s first!

  3. James

    This is a review of the Mariner 8x40mm WA. I had a chance to use these binos while boating, for general astronomy and for spectating at the 2018 Canadian Grand Prix this past weekend. BLUF, these binos represent outstanding value and are very good quality. Their key advantages are brightness and very good optical quality in the middle of the field of view. They also seem very rugged, but I did not test their ruggedness. On the less favourable side, the edges of the field of view were quite fuzzy, limiting the useful FOV by perhaps as much as a full degree but this was not noticed for any practical purpose. The other downside is the lack of a miliradian reticle. For a marine binocular this is a useful feature that aids navigation and costs little to add. It is a feature I would pay an extra $50 for. However the binoculars are useful while sailing without it. But I would ask that a bino strap with closed cell foam in a bright colour be included for all Marine binos so that boaters will actually use their binos rather than keeping them safe on shore.

  4. Jeffery Walsh (verified owner)

    I am an amateur astronomer but by no means an expert on optics. I do own a number of pairs of binoculars including Canon image stabilized binoculars (12X36 and 15X50.) I have been impressed with Oberwerk products that I have encountered at my astronomy club’s public observing sessions and decided to give the Mariner 8X40s a try. I keep them in a first floor laundry room closet as a grab and go pair for quick sessions in my yard. Construction of these glasses are, in my opinion, robust. All adjustable parameters function flawlessly and star images are tack sharp, perhaps the sharpest of all my binoculars. I have zero buyer’s remorse.

  5. laurie (verified owner)

    Although this was a very pair of binoculars, they were too heavy and not powerful enough for celestial viewing. Oberwerk was very good however about processing this return!

    • Kevin Busarow

      “Not powerful enough for celestial viewing” is subjective. The 8×40 Mariner was named “Editor’s Choice” for celestial viewing by SPACE.COM. More “power” is readily available, but comes at the cost of additional weight, as well the likely requirement for a tripod in order to have a steady view. We welcome (prefer actually) lots of questions before the purchase, to be sure you’re getting something that will meet your expectations, or to at least give us the opportunity to set realistic expectations, based on your desire for portability, as well as your budget.

  6. Gray Pendleton

    Excellent glass! They are meaty little binoculars and perfect in this size category, at a good price! Great work on these Oberwerk! The adjustable eye cups are a game changer. Very satisfied!!

  7. Tim Maxwell (verified owner)

    Delivered efficiently with impressive packaging and the quality control certificate inside. Very sturdy and easy to use. Looking forward to using them as often as I can! Definitely satisfied.

  8. Cris Guenter (verified owner)

    I have 10-30×60 zoom binoculars that are great for up-close bird watching, but not so great for looking at constellations. The design of the Oberwerk 8×40 Mariner binoculars is both thoughtful and efficient allowing for great views of the sky and things hear on earth. I was delight that I could also purchase a Oberwerk Heavy-Duty Binocular-to-Tripod “L” Adapter so I could put these binoculars on my tripod and keep them steady. The binoculars were well-packed and arrived with a strap, a carrying case, and documentation. This is a quality product.

  9. Dennis Jay (verified owner)

    Very well made and sharp image. Lens covers fit well and will not likely be lost. Good value!

  10. Don Uyhazi (verified owner)

    My email inquiry as to availability of the 8×40 Mariner is time stamped 12:01 AM. The reply is time stamped 12:04 AM; 3 minutes later, in the middle of the night! That’s my kind of company. My order went out later that day. The item was on back order at the time, but it was worth the wait. I’m completely satisfied with the 8×40 Mariner and with Oberwerk. Now that I’ve found this hidden gem of a company, I wouldn’t consider buying binoculars from anywhere else!

  11. Drew

    So far, so good! I already have the 8×56 LW models, they’ve been great also, especially for the low cost. I was seriously considering the Sport HD 8X42 which I know is a beautiful set, but couldn’t quite part with the money for now. I needed something for vacation at the beach where everyone felt reasonably comfortable with using, and that also had a wider FOV. This makes it easier to spot whales and dolphins since you don’t have to zero in so closely. This is especially helpful for those of us who aren’t comfortable with capturing objects at some distance away.
    At half the money of the Sport HD model, it’s a no-brainer for me.
    They have a very nice weight and feel. It’s taking a little time to adjust to the eye relief, the LW’s are a little longer in that respect; I wear glasses which always makes it a tad weird.
    Haven’t used them too much for the night sky yet, but with cool clear nights right around the corner here, I will be giving them a go. I haven’t seen too much difference in light gathering in day time usage between them and the LW which has a tad larger objective, but maybe that will show itself a little more readily at night. Having said that, I don’t expect to discern much difference at all.
    On merit alone? Nice glass! For the money? No secret there; Well done!

  12. Joe Doro (verified owner)

    Bought this for a grab and go out into the backyard to look at some stars and the moon awhen I don’t want to set up my 20×80 LW and for that purpose this is absolutely great. Came perfectly aligned. During the day terrestrial viewing is also perfect. Compared them to my old Cannon 10×30 IS and the images are brighter and clearer. I still use the Cannon when on the boat as the IS makes for easier viewing.

    BTW, this is a great company. My 20×80 LS got shook up in shipping and had some debris in the left barrel and were misaligned. I called and spoke with Kevin and he sent out a new pair that day.

    Also, the initial shipping charge when ordering was more than the actual, so the difference was refunded.

  13. Ryan (verified owner)

    I have been doing Astronomy for over 15 years and have gone through a handful of binoculars which I am very particular about since I wear glasses and need the eye relief, I discovered Oberwerk through cloudy nights and stargazers lounge forums. I originally was looking at the ultras and the deluxe series but read some great reviews of these mariners as I enjoy the large field of views so I decided to give them a shot.

    These 8×40 mariners are absolutely fantastic! I do want to note that the exterior is slightly different than what’s in the picture, the housing is the same but the rubber design is different and is actually nicer(same color). Everything else looks the same. They fit very comfortably in my hands. The overall feel of them is very nice and feel like excellent quality. The weight does not bother me even after long periods of holding them. When adjusting the IPD, the binoculars hold position very well, it requires some effort to change the distance which is great! Same for the center focus adjustment and diopter adjustment. Once you set these, they will not move on you for entire viewing sessions which is perfect for stargazing.

    While using them for astronomy, they give very nice sharp flat views. The visual you see through these binoculars to me is the same brightness you see with the naked eye which I prefer and is very nice with dark skies. I’ve been using them mostly in bortle 3-4 skies. I did not notice any CA from bright stars but did see just the faintest amount on the edge of the full moon which was a very faint lime/yellow color, but I was really looking for it! If your not looking for it, you will never notice it.

    For daytime use, these were excellent as well and you really see how sharp these are. The color is as true as it can possibly be, the lighting is exactly how your neked eye sees it. Looking at mountains far off in the horizon with mild blue atmospheric haze, the detail is sharp and you can make out the individual trees and rock formations. Surprisingly I did not notice any CA on the mountain tops, again I was looking for it.

    For birding and wildlife, just wow! The detail picks up hairs! We have cotton from the cottonwood trees blowing around and you will see them attached to plants, they are as sharp as can be! The only CA I saw during the day was on very bright reflected objects like metal frames or windows, and it was very faint, the lime/ yellow to magenta/ purple, I did not see any on edges of trees, or branches which I usually will always find with my other binoculars. I’ve used nikon prostaff 5 and a variety of vortex diamondback HD’s which are also nice but after comparing them, these mariners are way sharper, and handle CA better. These are absolute winners! Thank you Oberwerk! If there ever comes a 10×50 Mariner with good eye relief for glasses wearer’s, I will definitely be getting them.

  14. Eric Brindle

    I bought my pair in 2006. I bought them for 2 reasons. Wide angle views, and heavy duty construction. I have not treated these kindly.

    Over the last 16 years, they have been bouncing around my neck while hiking at least 1500 times.

    They are dumped into the rear seat of the pick up and usually a 10 pound back pack dropped on top of them. With out the case.

    They have been rained on so the screws are a bit rusty, and the rubber coating is a bit discolored in places from having been left in the sun.

    Still have perfect alignment. One of the best consumer purchases I’ve ever made.

    I’ll write again when they finally fall apart, but I’ll probably drop dead first.

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