Visibility while boating is obviously very important, but can be difficult due to reflections on the water surface. A good pair of marine binoculars is very useful onboard but what should you look for when purchasing? Here is a quick guide to choosing the right marine binoculars.
The magic numbers: 7×50
Binoculars are classed according to magnification power and the diameter of the front lenses. Higher magnification is not always better, as high-powered binoculars are harder to hold steady on target because they show a smaller section of the landscape. A 7×50 binocular is optimum for marine use.
The second most important thing to look for when it comes to marine binoculars is image stabilisation. The mechanics of these marine binoculars keep your image steady and help you avoid getting seasick.
It should however be noted that a set of marine binoculars with an extra-wide enough field of view won’t necessarily need image stabilisation.
Light Transmission and Coatings
Light is lost as it passes through binocular optics – sometimes as much as 50% in less expensive models. High-quality binoculars on the other hand will transmit between 80 and 90% of light.
Lenses are sometimes coated, typically with magnesium flouride, in order to increase relection and pass more light to the user’s eye. Avoid “full-coated” products and try to opt instead for “multi-coated” or even better, “fully multicoated”, sometimes abbreviated as FMC.
Field of View
This is the area you’ll see through the binoculars, expressed either in degrees or in the width of the area seen at a one kilometre range. A field of view of seven degrees (or about 115 metres) is usually considered optimum for general marine use.
Some marine binoculars feature “extras” such as a
- built-in rangefinder
These features can help you find magnetic north, and properly judge an object’s size and distance when the open sea can make it difficult to understand in relation to yourself. It does require practice to learn how to use these features correctly. However, once you do, you’ll need less gadgets on the boat with you.