Powerful Binoculars: Enhancing Your Boat Experience

When choosing binoculars for your boat, it's important to consider more than just magnification. While a higher magnification may seem appealing, it can actually make it harder to achieve a steady image when you're on the water. That's why most marine binoculars have a magnification of around 7x, which offers plenty of power while still providing a stable image.

One of the most important features of marine binoculars is waterproofing. Look for binoculars that are O-ring sealed and nitrogen-purged to prevent fogging. Some binoculars even come with a floating strap, so you don't have to worry if they go overboard.

Other features to consider include individual focusing, which allows you to adjust each eye-piece to your vision and doesn't need readjusting once set up. A reticle scale can be a useful navigational aid, and some binoculars even have a built-in compass that projects a compass bearing on the image.

When it comes to lens quality, look for binoculars with multi-coated optics that provide the best protection from glare and reflection on the water. BAK4 prisms are also superior to BAK7 prisms as they transmit light better and reduce internal light loss.

So, what are the best power binoculars for your boat? Here are some recommendations:

- Nikon Oceanpro 7x50 CF WP: These binoculars from Nikon offer a good balance of magnification and lens size, and they come with a floating neck strap.

- Fujinon Polaris 7x50 FMTRC-SX: These high-end binoculars from Fujifilm are perfect for heavy-duty use and feature a world compass and lens coatings for excellent light transmission.

- Steiner Navigator Pro 7x30: The latest generation of these binoculars from Steiner feature a ridged, water-repelling surface for a stronger grip and easy adjustments, even in rough seas.

- Barska Deep Sea 7x50 Floating Binoculars: These compact and lightweight binoculars from Barska are O-ring sealed and nitrogen purged, and they float if they end up in the water.

- Celestron Oceana 7x50: This gadget-heavy option from Celestron includes a built-in compass and a distance calculator dial, as well as a tripod adapter.

- Bushnell 7x50 Marine: These budget-friendly binoculars from Bushnell are waterproof, buoyant, and saltwater corrosion-resistant, and they feature a digital illuminated compass.

- Bresser Topas 7x50 WP: These German-made binoculars come with a built-in illuminated compass and a means of working out distance, as well as a floating belt.

Waterproofing and fog-proofing

Waterproofing

To be considered fully waterproof, binoculars must be completely sealed internally. This is usually achieved through the use of an O-ring seal, which creates an airtight barrier between the lenses, focusing mechanism, and chassis of the binoculars. This seal prevents moisture, dust, and other small debris from entering the unit. It is important to note that some binoculars are only water-resistant, meaning they can withstand light rain but are not intended to be fully or partially immersed in water.

When shopping for marine binoculars, look for those that are O-ring sealed and nitrogen-purged. Nitrogen-purged binoculars have had the internal air replaced with dry nitrogen gas, which prevents fogging and adds extra protection against corrosion. Additionally, look for binoculars that can be fully submerged to a reasonable depth for extended periods. This, combined with a floating strap, will give you time to rescue your binoculars if they fall overboard.

Fog-proofing

Fog-proofing is achieved by replacing the air inside the optical barrels with an inert gas, usually nitrogen or argon, which has no moisture content and therefore does not condense. This process, known as nitrogen-purging, ensures that your binoculars remain fog-free even in rapid temperature changes. Fog-proof binoculars also protect against the growth of mold and fungus on the glass surfaces, which was a common problem with older binoculars.

In summary, when choosing marine binoculars, look for those that are fully O-ring sealed and nitrogen-purged to ensure they are both waterproof and fog-proof. This will provide you with clear, uninterrupted viewing in any weather condition.

Magnification and lens size

When it comes to binoculars, the first number in the specification, such as 7x50, refers to the magnification, while the second number is the size of the objective lens. A larger magnification will allow you to see further, but the trade-off is that the image can become unstable, especially on a moving boat. A physically larger objective lens will let in more light, resulting in a brighter image, but the trade-off is that the binoculars will be heavier and more significant in size.

Marine binoculars typically have a magnification of 7x, which provides plenty of viewing power while minimising instability. This magnification strikes a good balance between making objects appear larger and keeping the image stable. A higher magnification, such as 10x, may be suitable for more stable vessels like pontoon boats that cruise on calm waters.

The ideal magnification for marine binoculars depends on the specific use case and the user's preferences. If you plan to use the binoculars primarily for navigation and spotting buoys, a magnification of 7x is generally recommended. However, if you are a birdwatcher or wildlife observer, you may prefer a higher magnification, such as 8x or 10x. It's important to consider the trade-off between magnification and image stability, especially in choppy waters.

In addition to magnification, the size of the objective lens is an important factor to consider. A larger objective lens, such as 50mm, will gather more light, resulting in a brighter image, which is crucial for low-light conditions like night-time boating or pre-dawn fishing trips. However, larger lenses also make the binoculars heavier and more cumbersome.

When choosing marine binoculars, it's essential to consider factors such as waterproofing, nitrogen filling to prevent fogging, individual eye focus adjustments, reticle scale for navigation, and a floating strap or buoyant design to ensure they float if dropped overboard.

Weight and portability

Marine binoculars seem to fall into two weight categories: the cheaper models, which tend to weigh around 600-700g, and the higher-quality models, which typically weigh around 1kg. The best option depends on your budget and specific needs. If you plan to use your binoculars for extended periods, choosing a lighter pair may be more comfortable and put less strain on your arms, wrists, and hands.

Compact binoculars are also available and can be a good option for small vessels like speedboats, kayaks, and canoes, where larger binoculars may be impractical. For example, the Steiner Navigator Pro 7x30 model weighs only 530g with a compass or 499g without, making it a good choice for rough waters. The Plastimo 7x18 Pocket Marine binoculars are another compact option, weighing just 160g, though their small size may be difficult for those with larger hands.

On the other hand, heavier binoculars may offer more features and better optics. For example, the Fujinon Polaris 7x50 FMTRC-SX binoculars, which weigh nearly 2kg, offer high-end features such as a world compass and lens coatings for improved light transmission. Similarly, the Nikon Oceanpro 7x50 CF WP binoculars weigh 1.13kg and offer a floating neck strap, a generous eye relief, and a wide field of view.

In addition to weight, the size and shape of the binoculars can also affect portability and ease of use. Well-balanced binoculars should be comfortable to hold and put less strain on your arms and hands. Some binoculars have a ridged, water-repelling surface that provides a stronger grip, such as the Steiner Navigator Pro 7x30. Others have a rubber coating or armour that improves grip and protects the binoculars from accidental knocks and water damage.

Rangefinder and compass

A rangefinder is a feature of binoculars that helps determine the distance and size of objects in view. Marine binoculars use a reticle rangefinder, which compares a scale or measuring marks on the reticle in the binoculars' field of view to the known size of an object being observed. This information is then applied to a formula to calculate the distance.

A compass, of course, shows direction. Some binoculars have a built-in compass, which can be essential for navigation and orientation at sea. Some compasses are illuminated, which can be useful at night, but these will require batteries.

• Hooway 7x50 HD Waterproof Military Marine Binoculars: These binoculars feature an internal rangefinder and illuminated compass. They are waterproof and float in water. They have a non-slip rubber armour and can be mounted on a tripod for increased stability.
• Bushnell Marine 7x50 Binoculars: Waterproof and fog-proof, these binoculars feature an internal rangefinder and illuminated compass. They have coated optics for increased light transmission and brightness, and the eye caps can be folded down to accommodate glasses-wearers.
• Vanguard Mariner Binoculars: These binoculars are waterproof and fog-proof and come with a floating neck strap. They have a built-in compass and rangefinder and an individual focusing system that allows for simultaneous adjustment and focusing.
• Konus 7x50 Tornado Marine Binoculars: These binoculars are waterproof and float in water. They feature a built-in illuminated compass and rangefinder reticle. They use BaK4 prisms and coated optics to maximise light transmission.
• Bynolyt Oceanranger Marine Binoculars: These binoculars have a unique shape that may be less easy to balance in the hand for some users. They feature a built-in compass and rangefinder reticle, with numerals for measurements. The compass light is powered by two small batteries stored in a hand-accessible battery compartment.
• Fujinon Polaris 7x50 FMTRC-SX Binoculars: These binoculars are designed for tough environments and are commonly used in the boating, yachting and fishing industries. They feature a built-in compass and rangefinder reticle. They are waterproof and fog-proof, with a protective rubber exterior.
• Steiner Commander Global 7x50 Binoculars: These binoculars are at the top of the range and feature a digital compass and rangefinder. They have a floating neck strap and a protective carry case. They have a sports-auto focus system, meaning that once set up, no further focal adjustments are necessary.
• Steiner Navigator Pro 7x50c Binoculars: These binoculars are designed with nautical use in mind and feature a built-in analogue compass. They are waterproof and have a high-grip rubber armour. They feature Steiner's sports-auto focus system, which means that once set up, no further focal adjustments are necessary.
• Minox BN 7x50 C Marine Binoculars: These binoculars are a good alternative to the Steiner Navigator Pro, with an integrated analogue compass and extra-large eye-pieces to accommodate glasses-wearers. They are nitrogen-filled and have a single eyepiece adjuster.

Eye relief and eyecups

When choosing binoculars for your boat, it's important to consider eye relief and eyecups, especially if you wear glasses. Eye relief refers to the distance between the ocular lens and your eyes when using binoculars, and it's crucial for ensuring you can see the full image without any dark rings or shadows on the edges. The ideal eye relief distance varies depending on the optical design of the binoculars, usually ranging from 10mm to 20mm. If you wear glasses, it's important to choose binoculars with long eye relief, typically at least 15mm to 16mm, to accommodate the distance between the lenses and your eyes.

Eyecups play a crucial role in achieving the correct eye relief. They can be adjusted to get the right distance between your eyes and the ocular lenses. There are three main types of eyecups: rubber cups that roll up or down, sliding eyecups, and twist-up/down eyecups. The twist-up/down eyecups offer the most flexibility, often featuring multiple "click" stops to help you find the perfect position. When using binoculars with glasses, you may need to fold or twist down the eyecups to the minimum setting, or only partially retract them, depending on the thickness of your glasses and the shape of your face.

When choosing binoculars, pay attention to the quoted maximum eye relief, especially if you wear glasses. Look for binoculars that offer generous eye relief, such as 16mm, 18mm, or even more. Additionally, consider the design of the eyecup—the best ones have multiple fixed "click" stops and allow for micro-adjustments to ensure the optimal distance for your eyes.

By adjusting the eyecups and achieving the correct eye relief, you can fully utilise the capabilities of your binoculars, whether you're navigating tricky estuaries, spotting wildlife, or simply enjoying the view from your boat.

Frequently asked questions