How Do You Use A Scuba Compass?

How Do You Use A Scuba Compass?

Navigating underwater is a vital skill that all scuba divers learn during the Open Water Course. A scuba compass is used the same as any ordinary compass, but it can be fully submerged into water, making it a crucial part of your equipment setup.

If you have ever tried to navigate using a compass, it is very likely the compass skills got the better of you at first. But if boy scouts and girl guides can tackle the challenge, then why can’t you?  

Now, you shouldn’t blame yourself entirely for the challenges that come with navigating using a compass. For starters, we rely so heavily on new technology such as smartphones, but taking the plunge underwater with your phone and trying to use the compass is not going to work…

Then there is the difficulty of using a compass underwater. Underwater, it can be difficult enough to maintain your balance, so strapping a compass to your arm and trying to keep it steady and held level doesn’t prove so easy at first.

So, for the compass-phobic divers out there (you know who you are…), I am here to tell you the easiest way to navigate while scuba diving using a scuba compass!

To help you out, within this article, we will cover the following points:

• Scuba compass anatomy
• Why are Scuba Compasses used?
• How to use a scuba compass while Scuba Diving?
• Practising navigational skills with a Scuba Compass
• Where do you put a Scuba Compass?
• Top 5 Scuba Compasses
• Dive computers with integrated compasses

Scuba Compass Anatomy 

Before you learn how to use a scuba compass, it is important to understand what it looks like and the components that make it function. Scuba compasses have four main parts: the card, the lubber line, the bezel, and a side window. 

The card is the round floaty piece that always points to the north, inside the compass. You want to select a scuba compass that has a simple and clear display.

In addition to the valuable cardinal points and normal tick marks, most compass cards will display the degree numbers too, which is quite helpful!

The bezel is the piece you rotate to mark your path. It displays 0 to 360-degree markings, and some fancier compasses also display north (N) and south (S).

Next is the lubber line, which is very important to help navigate underwater. The lubber line is a fixed-line on the bezel that you use to point and aim in the direction you wish to travel. 

If you are using a wrist-mounted dive compass, then you likely have a handy side window. The side window allows you to look through the compass horizontally and read your course. You shouldn’t only rely on the tiny side window, as you can only see the numbers, not the tick marks.

Why Are Scuba Compasses Used?

Scuba compasses are used for divers like yourself to successfully navigate underwater, on the surface, and above water to reach shore or the dive boat. 

You must be wondering, “why do I need a scuba compass if I am with a guide?” 

Here are the reasons why you should use a scuba compass on your next dive: 

• It will make you feel more comfortable should you experience poor visibility.
• You will save energy by reducing unnecessary swimming, and therefore, you will have better air consumption.
• They make your dive plan more effective.
• It can prevent separation underwater.
• They can help locate where the boat or shore will be after your ascent. 
• They are used for search and recovery underwater of dive buddies and dive equipment. 

OK, so now you know what a scuba compass looks like and why they are important, now let’s dive straight into how to use one!

How to Use A Scuba Compass While Scuba Diving?

To use a scuba compass while scuba diving, keep it flat and steady, following the degree marker inside the lubber line. If the marker moves, stop and realign yourself. To go back on yourself (reciprocal line), turn 180-degrees until the opposite degree marker is inside the lubber line. 

Using a scuba compass is not as easy as on land. There are certain ways you must hold it and how to navigate it. 

Part of using the scuba compass is the positioning. The scuba compass needs to be in front of you, in your line of vision, lying flat, so the card is not tilted. This is why the side window was a fantastic invention, as it allows you to see the card from the side without having to tilt the scuba compass upwards.

Remember to also take a heading before swimming off in your desired direction. This can be a specific bommie – animals move, so making your reference point where you saw that hawksbill turtle is not a great idea…

Once the scuba compass is level, you should be able to see the lubber line clearly pointing to a degree marker. This will be your line of direction. With your body aligned with your scuba compass, next, you need to set up your compass.

Allow the needle to find N, and then line up the bezel’s N index markings. To do this, make sure the N is inside the double hatch marks on the bezel. 

Once your scuba compass is set up, you can then point your compass in the direction you want to swim in. 

I know that’s a lot to take in, so, let’s put it in a common scenario! 

For example, if you need to swim back to shore during a shore dive, you have completed your safety stop but are lost, you can pop your head above the water, see where the land is and point your lubber line in that direction. Then, all you have to do underwater is follow the scuba compasses’ lubber line to reach the shore. 

While the lubber line is great for following, I’m sure you would agree that your body is not always perfectly straight underwater at all times… (as much as we strive for that perfect buoyancy!)

But do not fear, you can still navigate underwater, as the lubber line is also accompanied by numerical values. 

The value that you started with should still be inside the index marking with the lubber line pointing at it. If it isn’t, don’t worry, just stop, and realign the bezel, so the lubber line is pointing at the correct degree value. 

If you want to brush up on your scuba compass skills or want to add another speciality course to your books, why not take part in the PADI Underwater Navigation Course?

In this course, you will learn how to use a scuba compass properly, navigate making multiple turns, and be able to estimate distance underwater, all of which are vital skills to learn as a scuba diver. 

But wait, there’s more…

If you need to go back to your starting point, for example, let’s say you dropped your dive slate or dive knife, and you need to find it, then you can use your scuba compass. 

To return to your starting point, stop, and rotate your body until the N point is in line with the single hatch mark on the opposite side of the bezel. While keeping the marker inside the bezel, swim back on yourself to search for your missing object.

If you are in poor visibility or are diving in currents, it is highly likely searching for your missing object will prove difficult. This is where different underwater search patterns come in.

Read on to find out more!  

Practising Navigational Skills With A Scuba Compass

The power of using a scuba compass comes from your ability to navigate in different shapes, known as underwater search patterns. These are something you will learn when you become a rescue diver or if you take part in a search and recovery course.

The most common search patterns using a compass include the expanding square and a grid search.

Search patterns are used for missing divers and scuba equipment. There are two types you should familiarise yourself with. 

Expanding square:

This is the most common search pattern when using a scuba compass. This pattern is used when the missing item is within relatively close limits and diving in poor visibility.

Grid Search:

Also called the “U-pattern” search, the grid search is used when locating something in the immediate area. It covers a wide area, and it is best when two divers work together. 

Where Do You Put A Scuba Compass?

Scuba compasses can easily be mounted on your wrist, inserted into a console, or integrated into a dive computer. These three locations allow your compass to be stable, ensuring you get an accurate reading. The position of your scuba compass is crucial for it to function properly.

Unless you have your own compass, the one the dive shop lends to you may come in different types. 

The most common for scuba training is one you can wear on your wrist like a watch, however, some dive shops may insert it in a console next to the SPG to prevent divers from losing it underwater. 

Wrist Mounted Scuba Compass

Exactly as it sounds, wrist mounted scuba compasses are attached to your wrist, similar to how you mount your dive computer or a regular land watch. As your arm should be extended when using a scuba compass, you won’t be able to view it from above. 

Instead, you need to read it horizontally, so to do that leave your arm with the compass extended in front of you and place your other arm to form a 90-degree angle between your hand and elbow. 

This position also keeps the compass steady, so that you will get a reliable reading. 

Console Scuba Compasses

Now, don’t get me wrong, wrist mounted scuba compasses are super convenient, but for beginner divers, buoyancy can cause the card to tilt giving you an inaccurate reading, and then there is the risk of losing the scuba compass. 

Mounting a scuba compass in a console with an SPG makes it much easier, as you have a physical structure to hold out in front of you.

Scuba Compasses Integrated In Dive Computers

Many people are switching to dive computers that have a scuba compass built-in. Dive computers are also essential scuba accessories, so having 2-in-1 means you don’t have to carry multiple devices with you. 

Top 5 Scuba Compasses

Deciding which scuba compass can be overwhelming, but do not fear, I have you covered! 

Here are my top 5 scuba compasses (in no particular order) to take on your next dive.

• Suunto SK8 – the ‘box standard’ scuba compass used by most dive centres!
• Oceanic Dive Compass 
• Cressi Dive Compass 
• Sheerwood Dive Compass & Mount 
• XS Scuba Compass

Dive Computers With Integrated Compasses

With advances in technology, some dive computers now have integrated compasses. While they are not as reliable as a separate diver compass, they do save you the hassle of wearing another scuba accessory! 

Below are some awesome dive computers that also have a compass to help you navigate underwater. 

• Suunto D6i Novo
• Suunto D9
• Suunto Cobra3
• Vyper Air
• Mares Icon HD

Even though they are great, most people find that dive computers with integrated compasses do not perform as well as a separate compass.

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Final Thoughts

Learning how to use a scuba compass is a skill which can save lives. Knowing how to navigate back to the boat or shore is a vital skill to have, plus they come in handy should you accidentally drop something during a dive (trust me you don’t want to fork out extra pocket money to cover lost rental gear!). 

Scuba compasses are easy to use, and once you master the skill, compass navigation underwater and on the surface will become second nature!

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