How does a marine binocular work?

Sailing binoculars basically work in the same way as hunting or hiking binoculars, but differ in several features. After all, what is a disadvantage on land can become a real advantage on the water. Special marine binoculars are characterized, among other things, by a higher weight, wider field of view, and, of course, a waterproof housing. For perfect orientation, however, the marine binocular with compass and rangefinder is equipped accordingly. Would you like more information to choose the best marine binocular for your adventures on the high seas? Then we’ll gladly explain the most important buying criteria for sailing binoculars in detail.

Unlike magnification, the objective lens diameter can hardly be large enough. After all, a large lens also lets more light into the marine binocular – an important factor for safe navigation in the often adverse weather and lighting conditions at sea. For maritime use, the 50 mm lens has proven itself, allowing you to maintain a clear view even at dusk.

Bright excitement on the high seas – excellent light transmission

But it’s not only the objective diameter that affects light intake and thus image brightness. Light transmission – also known as light permeability – can be significantly increased by using high-quality materials. A marine binocular with BaK-4 glass (barium crown glass), for example, already delivers a brighter image than a sailing binocular with BK7 (boron crown glass), the standard for optical glass. Special coatings on the optical surfaces, such as full multi-coating, reduce disturbing reflections and bring more light into the darkness.

Everything in focus – eyepiece and autofocus

Unlike when observing animals or sporting events, focusing speed plays a minor role on the open seas and inland waters. That’s why marine binoculars typically use individual eyepiece adjustment or autofocus instead of a fast central focusing wheel. With individual eyepiece focus, you set the sailing binoculars once to your personal vision and then get a sharp image at all nautically relevant distances. With autofocus – also called fixed focus – the image is automatically sharp beyond a certain distance. Differences in vision between the two eyes are compensated in these marine binoculars by a diopter adjustment.

Heavier is better – weight

On board, great care is taken to manage weight. However, you shouldn’t cut corners when it comes to marine binoculars. A larger, heavier sailing binocular offers an important advantage on the naturally unstable surface of water: it results in smoother panning and fewer sudden shakes. To achieve the right weight, marine binoculars often use Porro prisms instead of the slimmer roof prism design. Special components for maritime use, such as a compass, also make the marine binocular heavier. And since binoculars are not constantly worn around the neck on board, the advantages outweigh the drawbacks.

Stays afloat safely – buoyancy

It happens faster than you think: the marine binocular goes overboard. To prevent your high-quality sailing binocular from being lost at sea, a floating strap is an extremely useful accessory. It prevents the valuable optical device from sinking forever. The straps also make it easier to spot thanks to their bright signal colors. This is an advantage that marine binoculars designed to float usually cannot offer.

Informed views – compass and rangefinder

Whether at sea, boating, or sailing – orientation is a top priority on the water. That’s why a marine binocular with compass and rangefinder can be a valuable companion on board.

At least one working compass is essential equipment on any boat or ship. So an integrated compass in marine binoculars is not strictly necessary, but it greatly simplifies navigation. You can determine the exact direction immediately while observing or even discovering an object through the sailing binoculars. If you regularly spend time on the water, a marine binocular with compass is definitely worthwhile. A practical bonus: an illuminated compass still shows the way at dusk.

And how does a binocular with rangefinder work at sea? Just like the compass integrated into marine binoculars, the rangefinder appears directly in the field of view. Using a reticle in the image, you can easily calculate the distance based on the size of the object.

Weigh anchor, set sail, cast off – we wish you fair winds and always a hand’s breadth of water under your keel!

Discover our high-quality BRESSER marine binoculars here