Marine Binoculars – What to consider?

I’m sure we’ve all been on a boat at some point in our lives and know how unsteady it can be. This unbalanced environment creates its own set of challenges when looking through a pair of binoculars. We’ll discuss some of the best features to look for when purchasing a pair of marine binoculars that’ll overcome the challenges you may face at sea.


Obviously, the main challenge when being on a boat is that you’re surrounded by a lot of water! So obviously, waterproof binoculars are absolutely essential. Many binoculars on the market today claim to be waterproof but this doesn’t necessarily mean they can go overboard and still function.

When purchasing waterproof binoculars, make sure they are O-ring sealed and nitrogen purged. This means the internals of the lens is pumped with nitrogen gas stopping the lenses from fogging up when there’s a sudden change in temperature. It also stops any internal corrosion from building up, a must for when you’re out at sea.

Some binoculars can be fully submerged, meaning they can go overboard and still function. When choosing a pair that can be fully submerged, check if it comes with a floating strap. Floating straps can be bought as an additional accessory if they’re not included.


When you’re out at sea what you’ll be trying to view will be far off in the distance. This, however, doesn’t mean you should get a super highly magnified pair of binoculars, quite the contrary.

Imagine zooming in fully on your smartphone or digital camera and trying to take a steady picture while being out at sea, it’s almost impossible! The same logic applies with binoculars.

If you buy a pair that has super high magnification, you’re not going to be able to keep them steady and reading the name of the boat passing you in the distance will be very difficult.

The most widely used magnification for binoculars at sea is 7x magnification. This gives you enough power to see far away objects while not compromising your stability. The magnification on a pair of binoculars can be found by the first number in the in the title (7x50).

If you require greater magnification than 7x, we’d recommend considering a pair of image stabilized binoculars. Image stabilisation dramatically aids unbalanced viewing experiences and keeps objects in focus while zoomed in at high magnification.

Objective lens Size

The diameter of the objective lens is measured in millimetres and is referred to by the second number in the title (7x50). The larger the diameter the greater amount of light your binoculars will let in. The more light a pair of binoculars capture, the brighter and clearer the viewing experience will be.  It also means you can use the binoculars later and earlier in the day (typically low light conditions).

One thing to keep in mind is as the objective lens gets bigger, the binoculars become larger and less portable. Now given you’ll be using these on a boat and have the luxury to pop them down when not in use, they don’t need to be super portable. We generally recommend an objectives lens of around 30-50mm, this size lets in an appropriate amount of light while not becoming too difficult to handle.

Type of Focus

There are two types of focus options when it comes to binoculars, autofocus or centre focus.

Autofocus binoculars are great when viewing items mid to long range, but aren’t advised for close up observations. Fixed focus binoculars have fewer parts under the hood, which means they’re generally the models that can be fully submerged. I’d recommend auto focus binoculars if speed is a factor and you don’t have time to focus.

Centre focus, uses a focusing wheel in the middle of the binoculars to move in and out of focus. Centre focus binoculars are much more versatile as you have the option to look at things up-close as well as in the distance with great detail. The downside is there are more parts involved and often they’re not able to be fully submerged.

Field of view

Field of view (FOV) basically refers to the horizontal distance you’ll observe given the magnification of your binoculars. Binoculars with low magnification, offer a wider field of view, so you’re able to see more. While those with a higher magnification, zoom you in significantly and provide greater detail, but lose sight of the surrounding objects.

When using binoculars at sea, you’d want a large field of view. In case of an emergency, you’d need a wide view of the horizon. The best way to decide is to find the widest field of view available, given the magnification you require.

Eye Relief

Eye Relief is an important factor if you’re someone who wears glasses. It refers to the distance from the ocular lens to where the image is in focus.

When wearing glasses and looking through a pair of binoculars, your eye is further away from the ocular lens compared to someone without glasses. This small incremental distance can have a substantial effect on your viewing experience. We recommend binoculars with the largest available eye relief with all other factors being equal.

Those of you who are near or far-sighted, we’d recommend using the binoculars without your glasses and adjust the focus wheel to focus in on objects. If wearing your glasses is a necessity while using your binoculars, or if you have astigmatism then we’d suggest a minimum eye relief distance of 15mm and above.

Our Top Picks

Here are some marine binoculars we think are the best performers in their class.

Steiner Marine 7×50

Steiner is known for their German engineered and manufacturing quality, only producing the highest quality binoculars. The Marine’s come with all the bells and whistles and can be fully submerged up to 2m deep. The extremely rugged and tough body is shock resistant and comprises slip-proof rubber armouring. They feature sports autofocus, so expect a clear, sharp and bright viewing experience at anything further than 20m away.

Byfield Optics Recon Polarised 10×42

These versatile high-quality binoculars are great for both land and sea observing. The polarised optical array allows for maximum light throughput and minimal reflectivity. They’re fully nitrogen purged, O-ring sealed, waterproof, dustproof and fog proof. The lightweight rubber design makes them great for on foot adventures or when you’re at sea.

Bushnell Marine 7×50

The Bushnell marines are a great pair of fully waterproof binoculars. Able to be fully submerged and still perform as new. They feature a shockproof, anti-slip rubber armouring.
The fully multi-coated optics and bak-4 prism make for a fantastic viewing experience. Feature sports autofocus, point them at anything over 20m away and you’ll have your object in clear sight. The marine also has a model with an analogue compass, if that’s a must.


Bushnell H20 8×25 Roof Prism 

This compact version of the Bushnell H20’s comes in a range of sizes (8×25 10×25 12×25). They comprise all the great features of the larger size models. They’re fully waterproof, O-ring sealed and nitrogen purged making them great in all weather conditions. The body is constructed of shock absorbent non-slip rubber armour and weighs only 290 grams. Experience a bright and sharp viewing experience with the bak-4 prism and multicoated optics and quickly focus in on objects with the large centre focus knob. These are a great compact pair of binoculars for both land and marine applications.

Saxon Oceanfront

The Saxon Oceanfronts are available in both 7×50 and 10×50. Not many binoculars at this price point feature a high-quality bak-4 prism and fully multicoated optics. They boast super bright & clear imagery for both land and sea use. They’re also waterproof, have comfortable fold-down eyecups and iconic yellow and black styling.



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