At OpticsPlanet.com we offer the best brand name waterproof Marine Binoculars from Bushnell, Nikon, Canon and many others! Most of our boating binoculars are completely O-ring sealed and nitrogen-purged for waterproof, fog proof protection in any season or weather conditions. We carry a number of models that Stabilized Image binoculars with high speed internal gyrostabilizing system that are perfect for the use on a boat in the sea or in any other moving conditions such as aboard an aircraft, land vehicles, sea vessels or other constantly moving, shaking, vibrating environments. Regardless of your needs for a tough marine binocular, we aim to give you the best bang for your buck. Below we have useful information on what you should look for in a binocular for boating. If all your questions aren't answered here, feel free to contact us and our product specialists will lend you a hand.
HOW TO CHOOSE A MARINE BINOCULAR
A marine binocular is a binocular that is used onboard a ship or boat and as such, it will have some fairly specific features. The vast majority of marine binoculars will be the classic 7x50, although other sizes can be used if they have the necessary features.
MAGNIFICATION - (the first number in a binocular)
Because the deck of a ship or boat is not a stable observing platform, magnification must be kept low for the sake of steadiness. 7x is by far the most popular magnification in a marine binocular and for good reason. A 7x binocular is easy to hold but also powerful enough to be a serious observation tool. Higher magnifications can be used, but unless they are combined with IS (image stabilization) systems, any gain in image detail may be lost to image unsteadiness. In fact, under marginal conditions, you may see more detail with a steady 7x than a shaky 10x.
OBJECTIVE SIZE - (the second number in a binocular)
The classic 7x50 marine binocular will have a 50mm lens. This is not just a matter of image brightness, though for night use, the 50mm objective will transmit more light than smaller objective. A 50mm objective, when combined with 7x magnification also produces a large exit pupil - the beam of light that leaves the eyepieces. This large exit pupil is much more forgiving than a smaller exit pupil when the eyes are not lined up precisely on the eyepieces, as might happen when you try to observe form the deck of a moving boat.
The classic 7x50 marine binocular is a porro prism, though, optically there is no reason a roof prism could not be used. The porro prism body, however, has more room to accommodate extras like a rangefinder and compass that are often found on a marine binocular. The robust body of a porro prism may also provide a firmer grip during inclement weather. The best porro prisms will be made of Bak-4 glass.
Both IF (individual eyepiece focus) and CF (center focus) systems are found on marine binoculars. - IF offers the freedom from focusing when viewing objects at medium and long distances - the usual range for marine use. Once set for your eyes initially, an IF binocular needs no focusing for objects beyond 30 or 40 yd. Just raise the binocular to your eyes and look. The advantage on the deck of a moving boat is obvious here. IF focusing systems are also the easiest to seal and make waterproof and they have fewer moving parts than CF systems. For this reason, they are also popular with the military. (Our military uses a version of the Steiner 7x50) - Center focus is a more versatile system. If you plan to use a binocular at all ranges, from close-in to far away, say for birding or other applications, this is the system to choose.
OPTICAL QUALITY AND PRICE
With porro prisms the most popular design, prices for the best grade of marine binocular will usually not peak out as high as in standard field binoculars. - For casual boating, you can get a very useable marine binocular for $100-150. - For a more serious marine binocular with solid optics and solid construction, you will be in the $250 to $400 range. Binoculars in this class will give many years of good service. - For those who want the most rugged instrument and the finest in optical quality, there are best binoculars by Steiner and Zeiss.
A compass in a binocular allows you to pinpoint the exact bearing of a target and share it with other observers who are using a compass in their binoculars. The compass also gives you a basic idea of direction at a glance. Because a compass is magnetic, however, it is subject to magnetic deviation which varies from location to location. No compass will ever be as accurate as a GPS. - On many models, the compass is illuminated for use at night (requires batteries).
In a marine binocular, this means a old-fashioned grid rangefinder, not a laser rangefinder. These grid rangefinders require you to know the size of the object (height or width) if you wish to calculate distance. If you wish to calculate the height or width of an object, you will need to know the distance. Math is required
Distance = actual height x 1000 Actual height = distance x scale height Scale height 1000
You can use any unit you wish since these equations are a ratio, but you must use the same units for all variables. For example, if you use feet for the height of an object, you will get a distance in feet, not yards or meters. You can convert to other units after you have your answer.
The good news here is that most 7x50 binoculars have good eye-relief. This means that you can use the binocular while wearing your glasses and still see the entire field of view.
This is a no-brainer in a marine binocular. Suffice it to say, anything less is inappropriate.
For marine use, you may need a binocular most when conditions are at their worst. For this reason, a good marine binocular will be fully multi-coated (FMC) for maximum image brightness. A model that is multi-coated (at least some of the lenses multi-coated) is next while a fully-coated (single layer coating only) model ranks the lowest in image brightness.
A true marine binocular will not only be armored, but also built extra tough to withstand dropping and sliding around on the deck of a boat. A good armor coat also helps to protect against the ravages of salt in ocean environments.
Since a marine binocular is not usually worn around the neck full-time and because a marine binocular must be built tough, weight will usually exceed what you find in a standard field binocular.