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The discontinued Oberwerk Mariner 8×40 is best known for its unusually wide 8.4° field of view, which can help when scanning the sky or tracking wildlife. Its waterproof, nitrogen-filled construction is a plus, but the 2.2 lb weight and 60 mm minimum interpupillary distance (IPD) make fit and handling important considerations. Oberwerk named the 8×42 Deluxe as its replacement; it is a different binocular, not a current version of the reviewed Mariner.
What the Oberwerk Mariner 8×40 offers
Oberwerk’s archived Mariner Series flyer describes the binoculars as rugged, waterproof, and nitrogen-filled, with metal construction under rubber armor and shockproof prism mountings. The 8×40 model has fully broadband multi-coated air-to-glass surfaces, oversize BAK4 prisms, a rigid center focuser, right-ocular diopter adjustment, twist-up eyecups, and a brass 1/4-20 tripod adapter socket. The package was described as including a padded rip-stop nylon case and a 1.5-inch denim strap. These are manufacturer specifications and claims, not findings from a new inspection. Oberwerk Mariner Series flyer.
| Specification | Oberwerk Mariner 8×40 |
|---|---|
| Magnification and objective diameter | 8×, 40 mm |
| Field of view | 8.4° |
| Eye relief | 18 mm |
| IPD range | 60–73 mm |
| Minimum focus | 5 m |
| Exit pupil | 5 mm (40 mm objective divided by 8× magnification) |
| Dimensions | 5 in long × 7 in wide × 2.5 in high |
| Weight | 2.2 lb (Oberwerk flyer); Space.com’s 2014 review separately reported 37 oz |
How it performed in the 2014 review
Space.com reviewer Dave Brody described the Mariner as a broad-view binocular for astronomy and outdoor use. He reported sharp star points, crisp lunar detail, and a wide field that helped with scanning. He also found the binocular substantial in hand and noted that its bridge could pinch the nose for his close-set eyes. Those are one reviewer’s observations from 2014, not results from a present-day test. Space.com’s 2014 Oberwerk Mariner 8×40 review.
That review listed an 8.4° field and 437 feet at 1,000 yards. It also gave a $150 street price at the time; that historical figure is not a current price. Space.com identified the model as an Editors’ Choice for Best Small Binoculars for Astronomy, a historical award rather than a current distinction or evidence of broad consensus. Oberwerk also referred to the recognition in a 2020 post. Oberwerk’s 2020 discontinuation post.
#1 Best Overall
- LONG-RANGE CLARITY: Premium Sport ED Binocular delivers powerful 8x magnification and a wide 8.1° FOV, making it perfect for advanced-level bird watching and wildlife viewing, or any application where flawless color rendition is necessary, rendering crisp, true-color images on long outings.
- SUPERIOR ROOF PRISM VISION: Oberwerk's signature broadband multi-coatings, dielectric and phase-coated prisms, ensure the highest-possible image quality. The internal focusers can focus as close as 6 feet away, giving precise subject lock and rapid adjustments in the field.
- ENHANCED USER COMFORT: Ergonomic design reduces fatigue during extended use while twist-up eyecups provide comfortable eye placement for users with or without glasses. Textured rubber armor improves grip and handling on long hikes and active excursions in varied terrain.
- WEATHERPROOF RELIABILITY: Whether bird watching, hiking, sailing, or exploring, you don't have to worry about the weather. The Sport ED binoculars are fully waterproof and sealed against moisture and dust, ensuring dependable performance in damp or challenging outdoor conditions.
- LIGHTWEIGHT MAGNESIUM-ALLOY CONSTRUCTION: Our Sport ED models are lightweight, yet durable, with dark green rubber armor over a magnesium-alloy body, with attractive red-anodized aluminum components. Twist-up eyecups help maintain optimum eye position for extended observation.
Fit, handling, and intended use
The 8.4° field is the Mariner’s standout specification: a broad view can make it easier to sweep across a star field or follow a moving wildlife target. But the binocular’s weight and minimum IPD can outweigh that advantage for some people. In a 2017 customer response, Oberwerk said the Mariner could feel bulky and heavy for a 40 mm objective and that its 60 mm minimum IPD could be too wide for some users. Oberwerk customer questions and answers.
- Check eye spacing: The barrels adjust from 60 to 73 mm. If your eyes are closer together than the 60 mm minimum, you may not be able to align both views comfortably.
- Consider the weight: At 2.2 lb in Oberwerk’s flyer, it is a substantial binocular to hold for long sessions. A tripod is optional; the 1/4-20 socket allows mounting with a compatible tripod adapter.
- Think about eyeglasses: The flyer lists 18 mm eye relief and twist-up eyecups. That figure alone does not guarantee a full field of view for every glasses wearer; fit can depend on eyeglasses and how the binocular sits against the face.
- Match focus distance to use: The listed 5 m minimum focus suits distant viewing better than close-range observation.
Mariner 8×40 vs. Oberwerk’s named alternatives
Oberwerk said in 2020 that the Mariner Series had been discontinued roughly ten years earlier and identified the 8×42 Deluxe as its replacement. Its archived 2023 chart also gives specifications for the 8×42 Sport ED. The figures below compare those models using Oberwerk’s flyer and chart; they are archived specifications, not confirmation of current product revisions. Oberwerk 2023 binocular chart.
Rank #2
- TOP QUALITY AND BUDGET-FRIENDLY BINOCULARS: A great pair of binoculars that combines top engineering features with an economical price. Perfect for backyard birdwatching, sports events, nature and wildlife viewing, hunting, travel, boating, concerts, and live events.
- EVERYTHING YOU NEED IS INCLUDED: Start your adventures today with this durable pair of water-resistant full-size binoculars. Accessories include: carrying case, objective covers, eyepiece covers, lens cloth, and instruction manual.
- TOP AMERICAN OPTICS ENGINEERING: These 8x40 powerful binoculars provide you with multi-coated BK-7 prism glass that increases light transmission, resulting in brighter and sharper images with high contrast levels and 8x magnification to get you even closer to the action.
- A DURABLE AND COMFORTABLE BODY: The Celestron UpClose G2 8x40 water-resistant binocular will be your event, birding, or hunting buddy for many years to come. The stylish waterproof exterior features a rubber-covered aluminum body, ergonomic thumb indents, and finger ridges for extra non-slip comfort and ease of use.
- UNBEATABLE WARRANTY AND CUSTOMER SUPPORT: Buy with confidence from Celestron, a leading optics brand based in California since 1960. When you purchase from an Authorized Dealer on Amazon, you will receive a Celestron Limited Lifetime US Warranty and unlimited access to technical support from our team of US-based experts.
| Model | Field of view | Weight | IPD range | Eye relief | Minimum focus | Waterproof / nitrogen-filled |
|---|---|---|---|---|---|---|
| Mariner 8×40 | 8.4° (Oberwerk flyer) | 2.2 lb (Oberwerk flyer) | 60–73 mm | 18 mm | 5 m | Yes; Oberwerk flyer description |
| 8×42 Deluxe | 8.0° | 2.3 lb | 56–74 mm | 13 mm | 10 m | Not stated in the cited 2023 chart |
| 8×42 Sport ED | 8.1° | 1.5 lb | 58–75 mm | 15 mm | 2 m | Not stated in the cited 2023 chart |
The Sport ED is much lighter in the archived figures, while the Deluxe has a lower minimum IPD than the Mariner. Those differences may matter more than small field-of-view gaps if weight or face fit is your limiting factor. The 2020 Oberwerk post names the Deluxe as the Mariner’s replacement; it does not make the models identical.
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The Mariner 8×40 is discontinued. Oberwerk’s 2020 post says the series had been discontinued roughly a decade earlier, so an online listing should not be treated as proof of current factory stock. No current official listing establishes present-day inventory, pricing, replacement parts, or a current manual.
If you find a listing, verify the seller, condition, included accessories, and whether the item is actually the 8×40 Mariner rather than a similarly named model. The historical Space.com purchase link does not establish current stock, condition, or seller terms. If you want a replacement option, consider the 8×42 Deluxe as a distinct model and check its current specifications and availability before buying.
Quick Recap
Best Value
- 8x magnification & 42mm objective lenses, these Crossfire HD binos are optimized with select glass elements to deliver exceptional resolution, cut chromatic aberration and provide outstanding color fidelity, edge-to-edge sharpness and light transmission.
- Fully multi-coated lenses increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces. Roof prism design is valued for greater durability and a more compact size.
- Fully multi-coated lenses increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces. Roof prism design is valued for greater durability and a more compact size.
- Rubber armor provides a secure, non-slip grip, and durable external protection. Binoculars are tripod adaptable allowing use on a tripod or car window mount.
- Nitrogen purging and o-ring seals provide water and fogproof performance in all environments. Rugged construction withstands recoil and impact.
Rank #4
- Powerful 8-16x zooming capability allows quick and easy changes in magnification to suit the viewing situation with excellent target resolution across the entire magnification range.
- High-performance optics provide a bright, clear field of view with superb transmittance and sharp, high-resolution images with minimal distortion and chromatic aberration even in low light conditions.
- Built with a durable, high-quality finish the robust housing resists any nature conditions - ideal for outdoor use. A rubber coated grip ensures a safe hold for easy and comfortable operation.
- Maximum comfort, functionality and portability are guaranteed due to a compact, lightweight size and ergonomic controls. The focus wheel is responsive and easy to operate even if wearing gloves.
- A rubber eyepiece and lens cover plus soft carrying case offer a solid protection. While the strap ensures a high level of wearing comfort and allows quick access to be ready for the next scene.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
