Binoculars come in many forms in order to suit the large number of activities in which they are used.
There are designs to suit bird watching and other hobbies, such as amateur star gazing. Other pastimes that may require the use of specialist devices include sailing and sea fishing. Marine binoculars are especially created to perform well in damp, salty environments and there are many types to choose from. Both amateur and expert sailors choose to purchase these instruments to get a good view of the surrounding water, which could highlight potential dangers.
Due to the rocking motion of boats and the conditions on the ocean, there is a lesser magnification value applied to these devices, compared with those used on land. This figure is expressed as 7x, which simply states that what the user sees appears to be seven times nearer than it actually is. In other binoculars, magnification is normally set at 8x, but this depends on individual models.
As well as magnification, marine binoculars can differ from terrestrial ones in other ways. For example, devices built to withstand the sea atmosphere have been hermetically sealed to protect them from moisture. These types sometimes contain nitrogen, which is a sure sign they are waterproof. However, not all instruments of this type are fully waterproof, though expert suppliers often suggest to sailing fans to buy those that cannot be penetrated by moisture.
Additionally, marine binoculars often have their lenses coated with special substances that boost light levels as much as possible, adding greater clarity during twilight and dawn, while many sailors like to opt for those devices that include compasses for navigational purposes.