Easy Diving | Navigating
Do you always surface in the wrong place? Can’t tell one end of a reef from the other? DIVE’s blogger Crowley (Mark Russell) lends a hand with some basic navigation tips
There are times, even to this day, where I wonder where I am. Usually this follows a long session in a bar somewhere, but even working as a guide and instructor, there have been times when I have found myself thinking ‘Where the heck am I!?’
Clearly this is not something a guide should admit to the folks following him, but even in the crystal-clear waters in which I prefer to work, it’s possible for even the most experienced diver to get a little disoriented.
If you’re familiar with one of my old haunts in Sharm, Jackfish Alley, you may have dived the plateau, which goes out to sea for a long, long way. It’s a good 15 or 20 minute swim in good conditions and after a while it’s almost flat, rather featureless and I admit to having a ‘moment’ once where I had very little idea where I was. It’s not a good idea to surface in the blue at this location – it’s very popular with dive boats and especially big snorkel boats – but after taking a moment to stop and take in my surroundings, check some visual clues and stick a metaphorical finger up to determine the direction of the current, everybody made it back to the reef plate, with ample time and air to spare. It turns out it wasn’t that confusing at all.
As a guide, clearly it’s important to get divers to and from a location safely, but what if you’re not with a guide? How can you determine where you are and where you should be? What if you don’t own a compass? Do you even need one? It has to be said that very often, in the resort locations where I work, that a dive centre will not allow you to dive independently at many of the local reefs. They may make exceptions for easy dive sites or house reefs, however. Most people are quite happy with this arrangement (including me, ‘cos I get paid to do it!) but if you want to find your way around a dive site with just you and your buddy, there’s a lot of tips and tricks you can use.
First off pay attention to the dive briefing - you may get separated from the group and need to orientate yourself. Or if you are diving as a separate buddy pair you can pick up some basic understanding of the site.
If you’re diving in poor visibility with limited features and unpredictable currents, then you need a compass and more advanced navigation skills. But I don’t really class this as ‘easy diving’. There are plenty of courses available for this, but this article is more concerned with sharing some basic techniques that help you avoid getting lost. Before I go any further, however, I would like to stress that not all techniques are valid in all locations, and it’s always advisable to take an orientation dive at an unfamiliar location before attempting to dive unguided.
At the surface
Before you even get in the water, gather some information by just looking at the dive site from the surface. Take a good look at the shore line and make a note of obvious features – perhaps a particular building, rock formation, radio mast or pylon – these will obviously serve no purpose underwater unless you use a compass to triangulate your position with them (courses available) but at a push, at least you can surface and re-orient yourself to reach your exit.
Have a look at wind and wave direction. If the visibility underwater is good, wave motion can easily be seen, and even if the wind changes, wave direction will take a while to catch up. Note the angle at which the waves are travelling. This can help you to determine which direction you should be swimming underwater.
Note the position of the sun relative to the dive site. If it’s on your left when you head out, then it will be on the right when you head back to the exit point. If you’re diving at night, lights from boats or the shore can often be seen for a good distance underwater, and can also provide a useful general sense of direction.
Many tropical dive destinations will involve reef diving. These often have similar characteristics: a shallow fringing reef plate from the shore, descending into a shallow slope, followed by a more dramatic drop-off into the depths. Navigation in this type of location is fairly rudimentary. Often you hear dive guides talking about diving ‘reef left’ or ‘on your right shoulder’ or similar. You may not know exactly where you are, but on a long, fringing reef, staying close to the coral means navigation is simple.
Reef topography is not always so convenient, however. Neither do all dives take place on reefs, so there are other topographical indicators that you can use to help you determine your direction. Depth is an easy one – it gets shallower the closer you are to the shore, and deeper further away from it; sand ripples are only found in relatively shallow water and are almost always parallel to the shore and beach because they are caused by wave action. I have used sand ripples at some point pretty much everywhere I’ve worked; either swimming across them, knowing I’m heading for shore, or along them while maintaining the same depth to find my way to a reef.
Meanwhile, an area with lots of broken coral either through natural or – unfortunately – man-made processes indicates a nearby shoreline, though it might not be the picturesque dive site you were hoping for.
The current at a dive site is often a good method of determining your direction underwater. In many places it’s linear – it runs along the reef in one direction or the other. So if you swim away from the reef into blue water, and the current is running from your right, then turning around and swimming with the current to your left should bring you back to the reef – albeit not necessarily to the same point, depending on the strength of the current. Having said this, remember that currents can change quickly and unpredictably, so advanced local knowledge helps as does common sense. Don’t keep swimming out into deeper water just because the current suggest you should be heading towards the reef.
Certain plants and animals behave in a way that is dictated by local currents. Many reef fish are territorial and remain in the same coral head for their entire lives. Look which way they are swimming, and how manically – this gives you a good indicator not only of the direction, but also the strength of the current. Sea fans always grow perpendicular to the direction of the prevailing current, so in slack water, away from the main reef plate, they can provide a good general indicator as to which way to swim to get back to the shoreline. At Ras Ghamila, back in Sharm, there is an awesome and infrequently dived northern part to the reef. The shoreline bends to the left, which means if you swim at slightly the wrong angle, you can have a long swim back to the reef plate. However, at around 24m, the reef plateaus out and there is a beautiful forest of huge gorgonian sea fans. To navigate back to the shore, which at this point is well out of sight, all you need to do is swim away from the fans with the ‘thin edge’ at your back and a few minutes later, you’re back to the reef. It’s a technique I often used when first diving that site.
We all know from our training that noise is not a good indicator of direction when diving, as sound travels much faster in water than through air. It can be useful, however, in a louder/quieter sort of way. Boat engines, or the sound of a compressor running, are quite obvious, but also consider that the presence and direction of boat activity can indicate a nearby jetty or resort, which must inevitably be fairly close to the shore. Listen for the clinking of chains that might be used as permanent moorings, something I’ve regularly done in many locations when the vis has been less than perfect.
The booming of waves against rocks, or the splashing of swimmers means you’re near the shore; even hearing a tank banger from a different dive group means that there’s somebody nearby – you can always follow them if you’re really lost!
Just like walking around on terra firma, simple observation is of great assistance, although of course visibility, even in blue waters like the Red Sea, is more limited underwater. More careful observation is required – and if you carry a slate, make notes: Entry from shore – block/line 5m / small coral block 10m, turn left, large porites 15m / right / sunken speedboat... can be helpful, then you just have to follow it in reverse. In many resort locations there will be other indicators – ropes and buoys at the surface which provide protected snorkeling areas – even the snorkelers themselves; if you see a lot of people splashing about in the water then you are surely close to a jetty or stationary boat, because most won’t actually swim very far. This could indicate the location of your exit point, or somewhere close to your own boat. At the very least, it’s a relatively safe point to surface if you’re not exactly sure where you are.
Remember that no single indicator is 100 per cent reliable. Although in general, large pieces of coral don’t move around very much, the characteristics of their surroundings can. Currents change, tides can rise and fall altering depth measurements, boats can move, jetties might be empty of snorkelers, waves and swell might subside, clouds may cover the sun, and even water visibility can change substantially during a dive, limiting simple observation. But all of these added together can provide a great deal of information. Even a compass is only an additional tool; rather like GPS in your car or smartphone, you should never rely on a single source of information to find your way around; good observation of your surroundings is required.
Remember that in the worst case scenario, there is always one available direction of travel, and that is up. If you’re diving without a guide, make sure you’re carrying some sort of surface signalling device (surface marker buoys are de rigeur); send up your balloon, ascend very carefully looking and listening for passing boat traffic, rest, relax and re-orient yourself; signal to your boat or shore support station if required, and ask for assistance if you need it. You might end up getting the mickey taken out of you in the post-dive pub session if you end up on the wrong boat or outside somebody else’s dive centre, but it’s better to come back to the wrong place than to never come back at all.
- Observe your general surroundings, not just the cool stuff in front of your face
- Communicate with your buddy; point out significant features to each otherν
- Look to the surface (if you can see it). There’s a lot of information there
- Simplify your compass use if you’re not familiar with navigation. Navigate around the cardinal points of the compass rather than taking precise bearings
- Lose sight of the reef or the bottom. It’s very tempting to follow that whale shark, but it knows where it’s going, and you don’t!
- Follow your buddy blindly. Diving is all about teamwork
- Swim in a direction which you can’t be certain of navigating in reverse. If you’re not sure, stick with what you know.
- Panic. The surface is only a few metres away. Carry a delayed surface marker buoy (please learn how to use it!) and a whistle, and if all else fails, get the balloon up, surface, and signal for assistance.