If you are comparing or buying binoculars for boating, sea exploration or even marine navigation there are a few considerations that can assist you in your decision. The following guide covers the most important features to look for in marine binoculars.

Magnification

Binoculars are generally represented as 2 numbers. The first number is the binocular’s magnification (or power) and the second is the binocular’s objective lens size. Typical magnifications are 6x, 7x, 8x, 10x, 12x, 15x and 20x.

The higher the magnification is the longer you will be able to see. With high magnification you will also be able to see in more detail. When out at sea you will normally look into far away subjects so one might think that very high magnification is idea. That is not really the case with marine binoculars.

The downside of high magnification is that the image becomes harder to stabilize while holding your binoculars. As you are on an unstable platform as it is (a boat) you will find it impossible to get a stable image by using high magnification binoculars.

“The ideal, and recommended, magnification for marine binoculars is 7x”

Need Higher Magnification?

For some, 7x magnification might not be enough. If you want more power in your marine binoculars you will need to stabilize the image also. A tripod is one way but even that will not work at sea. Since the boat is moving, so does the tripod. The only solution is purchasing image stabilised binoculars. These binoculars use electronic power (battery) to create a stabilised image. Image stabilisation is achieved by a press of a button. Canon, Fujinon and Nikon are considered to have the best models of image stabilised binoculars. Sizes vary from compact 8×25 binoculars up to big powerful 14×40 or 18×50 models.

Image stabilised binoculars are obviously more pricy but for many users they are definitely worth the investment. Especially for use at sea.

“With image stabilized binoculars you can benefit from higher magnification of your marine binoculars”

Best Lens Size for Marine Binoculars

As mentioned before, binoculars are represented by two numbers. The second being the size of the objective lens, measured in millimeters. Smaller lenses range between 20mm to 35mm. Small lenses make for lighter, more compact binoculars. Unfortunately small lenses also mean that less light comes into the binoculars. This becomes a problem if you want to use your binoculars during poor light conditions such as early mornings, dusk, fog and night.

Large objective lenses mean that more light comes into the binoculars. This makes for a brighter image as well as the ability to view clearly in low light. the downside is larger, heavier binoculars. For hiking, bird watching, hunting and general use this is an issue but not really for marine use. As the binoculars are kept on the boat, most users will prefer the larger lenses for their marine binoculars. 50mm is a great size which is still easy to hold and stabilize while providing a sharp, bright image.

“The ideal, and recommended, lens size for marine binoculars is 50x”

Waterproof and Fog-proof Features

This is of course a no-brainer.. If you plan on using your binoculars at sea just make sure they are 100% waterproof. Some manufacturers claim their models are waterproof while in reality they are more like water resistant. Make sure the binoculars were charge with nitrogen gas and sealed which makes them 100% waterproof. A safe option would be to purchase binoculars that are specifically made and marketed for marine use.

Marine Binoculars with an Added Compass

One common extra feature for marine binoculars is an added compass. The compass shows you a bearing when you look through the eyepiece and can assist in marine navigation. Some compasses are better than others. Some models of marine binoculars include a digital compass that is lighten and can be viewed at night. This is a nice feature but requires batteries.

Floating Strap

Binoculars will always come with a provided neck strap but some marine binoculars will also include a floating strap. A floating strap can come in handy if you accidentally drop your binoculars at sea. They allow the binoculars to float, hopefully long enough for you to pick them up and avoid their loss.

Brand and Cost of Marine Binoculars

There are many good models of marine binoculars around. Basically you pay for the quality of the optics. High quality binoculars will have fully multicoated lenses. This means that every single lens inside the binoculars was treated in a way allowing a maximum amount of light coming in and minimum reflection. The result is brighter, sharper, non-distorted edge to edge images. Another advantage of more expansive high quality binoculars is extreme durability.

They will never fog up and will pass the test of time regardless of how rough the conditions you use them in. Some of the known brands for marine binoculars are Nikon, Canon, Steiner, Vortex, Fujinon, Vanguard and many more. Prices can vary from $50 to $2,000 so it’s all about the brand, optics and special features that come with the marine binoculars.

Conclusion

In this guide we covered the essentials of choosing the best binoculars for boating, sea exploration or marine use. The ideal and recommended magnification for marine binoculars is 7x and the ideal lens size is 50mm. 7×50 binoculars or a more compact 7×30 will work well at sea. Remember to look for truly waterproof binoculars which were nitrogen gas filled and sealed. Models specifically designed and marketed for marine use are a safer choice. Additional features are a compass and an added floating strap. Expect to pay anywhere between $50 and $2,000 depending on the brand, model and optical quality of your marine binoculars.

Guest post by Procular. An Australia retailer for binoculars and marine binoculars.