Best Marine Binoculars For Boating
How to choose marine binoculars
A guide to marine binoculars
This simple guide will help you pick the right pair of marine binoculars for you and your boat. You'll learn exactly what the numbers mean e.g. 7x50, 10x50, etc. and what unique features are specific and important to binoculars that will be used in a boating environment.
Understanding the numbers on a binocular
The first number on binoculars
Every pair of binoculars comes rated with two numbers for example 7x50 or 8x30 and others but what do they mean? It's easy to understand once you know. The first number is the level of magnification so, if the rating is 7x50 then the image that you will see through the binoculars is seven times larger than what you would see with your naked eye. It's that easy.
The second number on binoculars
The second number refers to what is called the objective lens. The term objective lens just means the bigger lenses on your set of binoculars, the lenses that face the object you are looking at, not the ones you put to your eyes. The number tells you how big the lenses are, their physical size. So if your field glasses are 7x50 then the bigger lenses will be 50 millimeters in diameter. But why is the size of the lenses important? Don't we just need to know the magnification size? Well yes and no, let me explain.
Bigger lenses mean more light
It's not just about magnification
When it comes to choosing the best binoculars it's not all about the magnification strength. If you're looking at something like a navigational buoy or a harbor entrance, it might be magnified perfectly but if it's too dark then you won't be able to see it no matter how big the image in your lens is. So the second number is just as important as the first number but for different reasons. Each plays a critical role in seeing what you are trying to see. Here's a simple way to remember it:
The larger the second number = the bigger the lenses = more light (a brighter image)
So bigger is better, right? All you need to do is buy a set of binoculars with a big first number, a big magnification, and a bigger second number so that the image is bright and clear. Nope. There needs to be a balance so let's consider the factors that go into choosing the right size binoculars for you and your needs.
Bigger is not always better
Bigger lenses doesn't always mean a brighter image
A bigger objective lens number, the second number e.g. the 50 in a set of binoculars rated 7x50, does not always mean a brighter image. Why? Because even though you might have big, light gathering lenses on the front, increased magnification in the lenses on the back decrease the amount of light transmitted to your eye. Here's a rule to help you remember it:
More magnification = Less light
More light, meaning a brighter image, is extremely important, especially at dusk, early morning or when there is little ambient light to gather such as on a cloudy day.
OK, decision made then, you need a pair of marine binoculars that have a big magnification but that deliver an image that is still bright enough to still see. Wrong. There are other factors to consider, factors that are unique to a boat.
Boats & Binoculars
Binoculars on a boat
The difference between selecting a pair of binoculars for use on land versus for use in a marine environment starts with choosing the right magnification. The higher or more powerful the magnification the more unsteady the image is going to be and boats tend to move about quite a bit. Trying to locate and then hold a steady lock on an a highly magnified image while the seas are heaving and the boat is rocking is impossible so, nearly all experienced boaters agree that a magnification of seven is perfect. 7 = Heaven.
Field of Vision
Field of view
Being aware of what's happening around you is of paramount importance on a boat. You have to be aware of obstructions and hazards as well as other boats. The first time I sailed into San Diego it was a rough weather day, there were lots of boats out, quite a few hull-smashing Navy destroyers and a few, mammoth cruise line ships to boot. I was unfamiliar with the harbor so, with keeping the boat on course while avoiding the other ships and finding the navigational buoys, I had my hands full. Fortunately I have the right pair of binoculars and they allowed me to spot the numbers on the side of the buoys while still giving me a wide enough view that I could also see the boats around me.
Remember that sometimes you might be scanning the water through your eyepieces for an extended period of time while you search for a channel marker so a wide field of vision is definitely preferable.
Marine Binocular Review
The importance of marine binoculars
Why are bincoulars important on a boat?
Before we take a look at the other important characteristics that you will want to consider before you purchase your binoculars, let's discuss why binoculars are important to have on a boat. The most common use for binoculars on a boat is probably navigation, spotting channel markers, buoys and shore based landmarks. Knowing where you are at, especially in unfamiliar waters, will keep you from getting lost.
But binoculars are also an important piece of safety equipment too. Reefs, wrecks and obstructions floating in the water can wreck your boat faster than you want to believe and it happens more often that you might think. Sunken logs and other floating debris can breach your hull or snap off your rudder even in waters you know very well so being able to spot these things before you hit them is vital.
Lastly, binoculars are absolutely essential in the even of a man overboard situation. Being able to stay in visual contact with the person in the water is critical to saving their life.
Is fixed or variable focus better?
That little wheel that you sometimes see in the middle or on top of binoculars is the knob that allows you to adjust their variable focus which is sometimes called free focus. Most old sea dogs agree that variable focus is a distraction that can cause disaster. It's an outdated technology and is not a desirable feature for marine binoculars. Quite often, as he either holds on, works the tiller or adjusts the sheets, a sailor doesn't have two hands free to both hold the binoculars and work the variable focus ring.
Fixed focus binoculars
What is the difference between fixed focus and variable focus binoculars? Simply put, with variable focus binoculars you have to manually adjust them to keep an object in focus but with a set of fixed focus binoculars you don't have to adjust them at all. Fixed focus is far superior for the boater because it means you can quickly raise the binoculars for a look and then get immediately back navigating or running your ship.
Waterproof Binoculars are essential
Sure you'll be careful, but your binoculars are still going to get, that I promise you. Boating is a wet endeavor, it's just an inescapable fact so under NO circumstances should you purchase non-waterproof binoculars. Another thing you should definitely do is make sure they float if (and when) you accidentally drop them overboard. Seeing your spyglasses plummet to the bottom of the ocean is never something that puts you in a good mood and is an expensive mistake that is easy to avoid. My on own binoculars (same as the ones in the photo above) have a buoyant neck strap that is both extremely comfortable to wear and keeps my binoculars at the surface in the event of an unexpected 'water landing'.
Who said that?
Binoculars can fog up like a car windscreen on a rainy day and when they do you won't be able to see a thing. This highly dangerous scenario is the most common problem with marine binoculars but it is avoidable. Remember two things:
1) NEVER buy any pair of binoculars, no matter how great a deal you are getting, that don't have anti fogging. You may hear boaters talking about "dry nitrogen". It sounds fancy and high-tech but don't be intimidated because it really just refers to marine binoculars being filled with dry nitrogen as a means of preventing fogging.
2) Waterproof doe NOT mean fogproof.
You will drop them
Slips and falls are common on boats so it's in your own best interest to protect your purchase by making sure that the binoculars you buy are shock resistant and rugged. Binoculars are heavy and, in the wet-slick environment of a boat, can become very slippery if they aren't covered in the right material. A thick, rubber casing is best and it also makes them more comfortable to hold onto in both hot and cold conditions. This rubber coating has the added benefit of making sure that they stay where you put them and don't slide across the boat.
Binoculars with a built-in compass
One of the most valuable features of my own marine binoculars is their built in compass. The ability to quickly snatch a look at an object while simultaneously taking a compass bearing makes life so much easier and stress free. The alternative is to use one hand on the tiller, one hand for the binoculars and one hand on the hand bearing compass, which usually leaves me a hand or two short.
And it's not just about convenience either. The ability to take a bearing while looking at the subject through the binoculars dramatically increases the accuracy of your navigation. Being off by just a few degrees can mean serious consequences.
Know your distance
Binoculars with built-in range finders
I admit that I wasn't too excited about the range finder function on my binoculars until I started using it. Boy is it a handy little tool! It's a simple enough device to use, you just take the known height of a landmark you are looking at and then divide it against the graph you see in the eyepiece. It works very much like an unobtrusive HUD (Heads Up Display) on a fighter jet and can really be useful for determining your distance from shore or to an object.
The best marine binoculars
I only ever recommend things that I have used myself and have direct experience with so, after several years of using the Vanguard Marine Binoculars, I cannot praise them enough. These 7x50 binoculars are ruggedly constructed, armored with a shock-resistant rubber casing. They are both waterproof and 100% fog proof. They have the most valuable navigational aides including a built-in compass with a red, night vision friendly compass light as well as an internal range finder. Watertight up to five meters but with it's slip resistant skin and floating neck strap I will never have to test that.
I regularly shop marine binoculars to compare the latest releases with what I have and, to date, nothing else even comes close, especially for the price. Hope this guide helped you pick the right pair for you. Happy boating!
The best boating binoculars
Useful or Not?
Did you find this useful?
Back Up Your Data Before Boating
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2012 Dale Anderson