Dive Like A Pro: How To Use A Compass For Navigation

How to use a compass for navigation
How to use a compass for navigation

Our panel of experts discuss how to navigate like a pro – or, at least, how to look as if you know what you’re doing with a compass!

Dave Lock, BSAC’s Instructor Training Group Leader: “There are lots of ways to get lost under water, however some divers seem to have an infallible instinct for returning to the surface in the right place. Constantly using a compass to navigate is not only boring but distracts from your dive. It’s a useful instrument, and most divers own one, but many don’t know how to use it.

“Dive agencies teach the use of a compass for straight-line exercises but how many times do you dive just following a compass, or just swim in a straight line? Another way to navigate is pilotage, but combine this with compass navigation and you’ll look like a pro.

“Pilotage is using features of the underwater scene such as parts of a wreck, sand ripples or recognisable features of a reef. Wrecks that remain ‘wreck shaped’ are easy to follow around the edges and you can move to the centre if you identify a major part of it so that you can return to it. Using a compass on a steel wreck is not going to work too well, so you’ll need to use pilotage in this case.

Sand ripples can indicate the direction of onshore waves or of the prevailing tidal stream. This can indicate the direction of the shore or, if you get it wrong, the way to a long swim back.

“In warmer waters the reef wall is an easily recognisable feature, along with large coral outcrops.

How to use a compass for navigation
How to use a compass for navigation

“So how do you use your compass in these scenarios? You could just use it to swim in a general direction with an occasional glance to indicate that you’re swimming in the correct direction. You could also take a bearing on a distant visible item, and then use the reciprocal to get back to your starting point. 

“Using a series of these will allow a complex route and return to be made. Of course, if your memory is like mine, you’ll need to write these down. Some computers have an integral electronic compass that can be used to set a direction and will remember the course so thatyou can easily return on the reciprocal.

“We’ve not mentioned distance, another important factor to underwater navigation. The use of a dive computer for timing is a standard way to estimate distance swum so that an approximate return can be made using the same timing information.

“So what do you do when you get lost? Cheat, of course! If the dive is not too provocative you can surface to check your way home. Otherwise, put up a DSMB and await getting picked up and pretend it was in your plan in the first place…”

RAID UK & Malta Director of Training Garry Dallas: “You don’t need courage, ego or adrenaline to be able to lead your friends competently and safely on a dive – use a compass. It just takes technique, trust and practice!

“As an avid scenic reef diver, you might become familiar with certain objects, shapes and surroundings as you frequent your dive-site. This builds a confidence that is rarely surpassed, except when night falls or visibility deteriorates. Here’s when that tiny bit of equipment comes in very handy.

“When we don’t know how to do something properly, it prevents us from practising. Lack of practice prevents us from using it, so learn how to use a compass properly – it’s very gratifying!

“Your buddies will be amazed when you can navigate them to a site and back again efficiently! Learn to trust your compass readings, and follow it exactly to the mark, especially if you feel the onset of narcosis. 

“Midwater compass use is especially useful when you don’t feel the effect of actually getting anywhere – commonly when you feel the need to ascend to a shallower depth to conserve gas. Trust your compass!

“When sea currents push you in different directions, you can alter your trajectory according to your prime direction because it is your reference. Without the compass, you’re just guessing.

“Keeping your kit streamlined is important, too. Dangling compasses have a tendency to be ripped from your harness/BC D-ring. I must have found a handful over the years, lying on a quarry floor or seabed. Also, to use one in a competent and effective manner, without disturbing your trajectory or making you inadvertently drop your knees, depends on where you place it on your person.“

“I found a particularly useful place to mount it, which is on the back of your hand using a bungee mount, with the forward loop crossing over the rear loop and over the thumb. It can be pulled back over the wrist and left on your forearm when not needed, and easily pulled over the wrist to be deployed and used.

“The bonus with this method is that it keeps the palm of your hand and all your digits free. The double bonus is that you can alter the window of your compass to suit your relaxed arm reach by adjusting the bungees on the fly.”

Compass mounted on the back of the diver’s hand using bungee

IANTD’s Tim Clements: “Some might say the best way to navigate like a pro is to get your students to do it all! That doesn’t really cut the mustard in terms of supervisory responsibility. Others might get super-intense about compass work, but this is only one tool among many we can use, such as sand ripples under water.

“The skill of a pro is to be able to stitch all the techniques together to be able to cope with plan A or plan B and still get back safely. Nav is also a skill that is most easily lost through distraction, and a pro in charge of students is already distracted. 

“The first key skill is planning. Be very familiar with the site, other info, tidal currents and the weather outlook. Make sure you have a good gas plan for contingencies or additional swimming. During the dive, be proficient with pilotage (natural features) and be a very competent compass-user. It’s too late to figure out a compass when you’re lost!

“The overall skill is awareness. Keep checking your status, the team status and the dive / plan status. Early warning of issues is key to avoiding navigational issues or changing to an alternative plan. 

“One excellent tip is to look backwards as you swim out. This is the view you need to see on the way home…”

Mark Powell from TDI: “Where’s the boat? Did we pass this part of the reef already? Should we just go up? Whether it happens to a new diver or an experienced one, there will more than likely come a time when navigating under water will become difficult. 

“For a new diver who is excited to experience the underwater world without an instructor, the difficulty might come when it’s time to head back to the boat, or when the buddy-team gets turned around. 

“An experienced diver might have trouble when diving in a new place where conditions are not what they’re used to – for instance, a diver who is used to the visibility in an ocean and travels to a quarry and experiences less-than-decent visibility for the first time. 

“All the silt from the bottom that’s been stirred up from the day before could cause an open water diver to lose track of their surroundings. This is when being not only being able to navigate by sand ripples under water or with a compass comes in handy, but when other methods of navigation can and should be utilised as well.

“1. Know your compass. A diver should know what the parts of a compass are and what they are used for. The card is the part of the compass that always points to the north. It will display N, S, E and W. The card is shaped a bit like a dome, with degrees shown on the face. These numbers will allow the diver to see in which direction they are traveling – for example, 220°SW.

“The lubber line is used to point the buddy-team in the direction in which they want to go. The person in charge of the compass should hold it out in front of them and in line with their body.

“The side window of a compass is used along with the lubber line. When the lubber line is pointed in the direction in which the buddy-team want to travel, that window shows the degree to which the team is heading.

How to use a compass for navigation
A buddy-team needs a leader, but teamwork still helps

“The bezel remembers the original degree setting. Once the lubber line is set in the direction of travel, the leader of the buddy-team will have to turn the bezel to where the card points to North. Make sure to put the ‘N’ between the two tick-marks on the bezel.

“2. Listen to the boat briefing, or ask a dive-shop about a particular shore site. Knowing a bit more about the orientation at any given site will not only help you plan your dive based on what you want to see, but also help you with navigating.

“3. Elect and follow a leader. When planning a dive within a buddy-team you’ll want to delegate a person as the leader. This person is going to be in charge of the compass. To avoid leaving the other member of the team out, they will need to help guide the leader by looking out for obstacles, as well as possible landmarks.

“4. Monitor your time. On a boat, the captain will normally give you the amount of time they will allow open water divers to stay under water. Using a dive computer as a reference will help you to do a little maths to figure out how long the buddy-team has to look around the underwater world while still having enough time to return. If a shore dive is being planned, the buddy-team will want to decide on a time collectively. In both cases, the divers will need to make a point of setting their air limits to stay safe.

“5. Get to know your surroundings. Keeping in mind the dive briefing for the site, the next step is to look at your surroundings and keep in mind what you’ve seen around the boat. Once the buddy-team has decided on a direction of travel, noted the degree you’ll need to set to travel back to the boat on your compass, and set your lubber line for the direction in which you want to travel, the team can continue on their adventure. 

“Once on your way, look out for landmarks and either make a mental note or, if you have one, write them on a slate. This will help you to follow a path, if one is not apparent under water. Remember to check your compass as well as your air and time to be sure that you’re staying within those limits.

“6. Stop, Look, Listen. If for some reason the bezel on the compass got bumped and you can’t remember the directional degree you need to reach the boat, you’ll want to keep in mind these tips. First, stop and think about your dive thus far. Second, look around for the landmarks you noted along the dive. 

“Third, listen for the boat’s engine. Remember, sounds travels four times faster under water than on land, and although it might be harder to work out where the sounds are coming from, you might be able to pick out the general direction of the boat. 

“If all else fails and you think you might be way off course, ascend at the appropriate rate and look for the boat at the surface. Once you spot it, take a new heading and follow that. If you’re doing a shore dive, you can look at the pattern in the sand and follow that to shore. You’ll quickly notice that your depth gets shallower and shallower.

“7. Practise. As with anything else in life, the best thing you and a buddy team can do for your skills is to practise. To do that, all you need to do is get out and dive. Remember to incorporate your compass and other navigational skills into every dive you do and you’ll keep getting better and learning more about navigating in an underwater environment.

SSI’s Andy Rose: “Disorientation and that feeling of being lost under water is a sure way to ruin a pleasurable dive. You wouldn’t start a journey without an idea of the route to take in your mind, and a dive is no different. Time spent preparing the navigation element of the dive plan and agreeing it with your buddy or team can save a lot of unnecessary stress under water. 

“How does that dive-guide seem to know just where they are throughout the whole dive, when to you the topography all looks the same? It’s all about familiarity. Navigation training in the Open Water and Speciality Diver courses will teach skills and techniques that can help you navigate during your dives, but good navigation is an art. It’s only by spending time in the water that you will develop these skills and build the familiarity with the site to allow you to navigate with comfort and ease.

“When diving new sites, gather as much information as you can prior to planning your dive. Charts, dive maps, information from local divers and tide and current information can all help you plan and visualise your route prior to entering the water. When diving in a new location don’t try to cover too much ground on a single dive. Become familiar with an area before pushing further. 

“If you have limited time in a location and want to achieve a specific goal, consider hiring professional assistance. There is no shame in paying for a professional guide to orientate you, or even to look after the navigation while you focus on getting that perfect photo. How many experienced mountaineers would attempt a climb in a new area without employing local guides?

“Remember, good compass skills will help you but only if you know where you are and where you want to get to. Spend some time to know and understand your dive site – a knowledge of its water movements and its recognisable features will help you every time.”



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