MARINE & SAIL BINOCULARS - WATER SPORTS AND THE RIGHT BINOCULARS!
The professionals among you will certainly have dealt with the subject of sailing binoculars/naval binoculars and their special features, but with this report we would also like to give laymen and sailing beginners a brief overview of the special requirements of sailing binoculars/naval binoculars.
First of all, it is very important to clarify the difference between compact binoculars with a standard eight or tenfold magnification and sailing binoculars/naval binoculars, which are specially designed for seafaring. Although the weight of the cargo is carefully considered on board, a larger and more robust marine binocular is usually used, which has several advantages. In order to be able to see relatively well in twilight, the light transmission must be good. In addition, for orientation on the high seas, for example when searching for a heading buoy, a wide field of view is needed to be able to survey a large section of the image. These requirements are optimally exploited with a 50 mm binocular lens, high light transmission and an exit pupil of 7 mm. An exit pupil of 7mm is perfectly adequate, since in old age the human pupil only reaches a maximum aperture of five to six millimetres anyway..
Now, however, there is a conflict of aims between magnification and freedom from camera shake. Binoculars with eight or tenfold magnification are excellent for use on land. At sea, however, the image would be very blurred, as even a minimal sea state has a very negative effect on the image quality. In order to find a compromise, most sailing binoculars/naval binoculars have been chosen with a sevenfold magnification and a heavier weight, as a heavier glass leads to a more damped panning motion and less jerky shaking.
The heaviness is due to the well-known porro construction and the larger housing. On the one hand, the porro construction ensures a higher light transmission than with roof binoculars. As a small relief, it can be said that the weight does not lead to any great physical strain or restriction, as marine binoculars are usually suspended in certain places and only needed for certain actions.
Now that the technical requirements with good light transmission, sevenfold magnification and wide field of view have been explained, there are some important equipment options. Firstly, sailing binoculars/naval binoculars should be rubberised at least at the mounting surfaces so that the binoculars can be held firmly in place even in rain and storms.
In addition, the water resistance of marine binoculars is of elementary importance, as they must also be functional in heavy rainfall and high wave action. In addition, you should consider a floating harness for the binoculars, as otherwise the high-quality sailing binoculars or marine binoculars would be immediately lost on the high seas if they were to fall into the water. Therefore, the depth of water resistance, which has recently been increasingly specified by companies, is not of great importance, as the binoculars with a floating belt will float no more than half a meter below the water surface. Of course, binoculars that are already buoyant are a good alternative, but you should bear in mind that if you lost them, it would be very difficult to find them again on the water.
Furthermore, an integrated compass is not absolutely necessary with binoculars, because almost every ship has one or more compasses on board. Nevertheless, sailing binoculars/naval binoculars with an integrated compass can make your work much easier.
In conclusion, it can be said that sailing binoculars/naval binoculars cannot be compared to normal binoculars or compact binoculars, because the requirements and specifications have to be adapted to the actual purpose.