Top 10 Marine Binoculars for 2024

When at sea, use of marine binoculars is necessary for enhancing the safety of the vessel. Though there is no specific regulation in SOLAS on the number of binoculars present on vessels, it is important that all vessels are equipment with best marine binoculars.

As a mariner, it is important to know about the binocular (and its features) you are using at sea to ensure you are having the correct one and in case there is a need of upgrade.

What you should know when using or buying a Marine Binocular?

There are usually five important things that you must know when it comes to knowing your binocular. They are:

1. Magnification and Lens Diameter
2. Focus
3. Field of view
4. Waterproof/Fog proof

Most commonly used marine binoculars are of 7×50 type. This means that the binocular has a magnification of 7x and the objective lens diameter of 50 mm.

If you want to purchase the best marine binocular, this is the first thing you will look at – the magnification and the lens diameter.

Let’s understand each of the above features.

Magnification and lens diameter:

Binoculars are categorised in numbers – 7×50, 7×35, 8×25 etc. , where the first digit is the magnification and the second is the diameter of the lens.

At sea, it is obvious that higher the magnification, greater the information we will be able to gather through our eyes.

However, it is to note that, as the magnification increases, the harder it gets to keep an object in view, making it blurry as the brightness reduces. To prevent the reduction in brightness, higher lens are required to increase the brightness of the image. As the size of the lens increases, so does the size of the camera, making it bulky and uncomfortable to use.

Moreover, the distorted and blurry image is further spoilt by shaky hands and swaying movement of the vessel.

Therefore, it is advisable that marine binoculars have a conservative magnification of not more than 7x with objective lens diameter of 50mm.

Focus :

Center focus or Individual Focus

Marine binoculars usually come in two variants – centre focus and individual focus or fixed focus .

In centre focus binoculars, there is a knob at the centre which simultaneously changes focus on both eyepieces. This is a traditional type of binocular and is helpful if you would be sharing your binocular with the rest of the crew (As everyone can adjust focus according to their need).

Center focusing is the most common type of binoculars available in the market.

However, most of the marine binoculars are of individual focus variant.

Advantages:

– Ergonomically easiest- Knob is easy to use
– Focus really close objects

– They can be used for even the shortest distances.

– They have better resolutions as well
– Good for those with eye glasses ( have movable eye cups)

Disadvantages:

– Difficult to waterproof them. – Have difficulty with watertightness and internal fogging

– It takes time to focus every time it is used

Individual focus (Fixed focus):

In individual focus marine binoculars, focuses of each eyepieces can be separately managed.

This prevents the need of adjusting the focus every time the binocular needs to be used. This saves a lot to time, especially in emergencies at sea.

Advantages 

– Focus only once. There is no need to focus again. The eyes do the focusing for you even with varying distances.
– In low light situations, it is difficult to focus in center focus binoculars whereas in individual focus came, as the focus was already done before, it is easy to focus on the object.
– Most of them are waterproof (more easier to make them waterproof)

Disadvantages

– Difficult for close focusing
– Difficult to use for those with glasses. Most have eye cups that are not adjustable.

Field of view:

Field of view is typically the measurement of width in feet or meters from a fixed point. It describes the image visible horizontally when looking through the binocular without moving the same.

Field of view is measured in feet at a distance 1000 yards or meters. Each degree of view is equal to 52.5 feet at 1000 yards.

It is to note that the field of view and magnification are inversely proportional. Which means if magnification increases (with smaller objective diameter), the field of view of the marine binocular decreases and thus narrower will be the image.

For marine binoculars, it is important to have the widest field of view.

Eye relief:

Another thing that needs to keep in mind is the eye relief of the marine binocular. It is the distance between the eye and the ocular lens (eyepiece). It is important to maintain the right distance to view a sharp image.

Usually, eyecups are installed on the eyepieces so that the viewer’s eyes are at a proper distance from the eyepieces.

Those wearing glasses, needs to be careful as the eyepieces will be positioned past the eye relief distance, which will give a blurry image and reduce the image quality.

Though, almost all marine binoculars come with adjustable eyecups, which can be pushed back inside to allow placing the eyeglass lens closer to the ocular lens and maintain the eye relief.

Waterproof/Fog proof:

Considering the type of harsh environment marine binoculars are used in, they must be waterproof and resistant to fog.

Waterproofing in binoculars is done by sealing all the opening with O-rings. This helps in keeping dust and moisture from entering the binocular body.

Almost all waterproof binoculars are filled with dry nitrogen gas at a pressure higher than the normal atmospheric pressure. This positive pressure prevents lower pressure outside air or moisture from entering the binocular. Also, nitrogen gas cannot hold any moisture, and therefore the water cannot get inside the binocular body. Though waterproof binoculars are internally fog-proof, moisture can still condense on the outside of the lens.

However, it is to note that just because a binocular is termed as waterproof, it cannot withstand full submersion in water. Some superior binoculars do have waterproof feature until certain submersion depth and a specific amount of time, which is specified on the binocular.

Do remember that technically, all fog-proof binoculars are waterproof. However, not all waterproof binoculars need to be fog-proof.

Additional features:

Nowadays, several high-end marine binoculars come with more advanced features which might make your life easier at sea.

Some of these features you should look out for are:

Floating strap:

Some of the marine binoculars come with a floating strap whereas sometimes you might have to buy it. If you are investing a good amount of money in a marine binocular, it is important that you invest a few extra in an adjustable floating strap which would protect your binocular if it goes overboard.

If your marine binocular is waterproof, that’s good, but then if your optics go overboard in deep sea, then that would be the last time you will be seeing them.

Floating straps are made with high buoyancy materials which prevents them from floating should they fall in water.

Compasses 

A few marine binoculars available in the market also come with a built-in compass. They give a superimposed compass just below the image while viewing through the binocular. This comes very handy while observing any vessel at a distance and knows its direction. The compass feature is highly useful from safety point of view of the vessel.

Some marine binoculars also come with digital compasses and the system is illuminated as well.

Rangefinder reticule 

Rangefinder is an added feature which is provided in many marine binoculars. This binoculars come with an integrated infrared laser system which helps in measuring a distance of a vessel or object from the binocular. They are very handy at sea, especially in emergency situations.

The distance is generally displayed in meters or feet and the readout is visible directly in the eyepiece.

Some marine binoculars also come with inclinometers.

Image stabilisation

Image stabilisation technology first came in digital cameras. Several major companies that make marine binoculars incorporated this technology in binoculars, which helps in compensating the observer’s movement or swaying of the vessel.

Marine binoculars with image stabilisation technology are fitted with a gyroscope which helps in reducing movement in high powered binoculars.

Best Marine Binocular