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Real navigation in scuba diving

Navigation in scuba diving is seen as something of a dark art.

We have heard many, many scuba divers comment that they could never navigate a dive, even sites that they may have dived on multiple occasions.

Some have completed one of the navigation courses offered by the various diving agencies and so should, at least in principle, be confident enough to navigate underwater.

The reality is that they may be competent in using a compass - even if a little refresher would be needed, but don’t feel competent to navigate a dive.

It seems that being able to navigate triangles and squares is more an exercise in underwater maths, than truly being comfortable and ready to navigate for real.

Whilst we are all for caution, we are also all for divers having confidence in their own competence. We sometimes question whether the standard navi courses offered in scuba diving deliver this?  

Responsibility not maths

Navigation is about responsibility. 

It is about taking on the responsibility of getting yourself, and anyone else you choose, back to where you were all expecting to be. It is also about the responsibility of not going ‘too far’ so that you pick up an unexpected current.

But that is only if you decide to lead a dive. 

Regardless of whether or not you choose to take on the responsibility of navigating a dive, there is a  fantastic reason to learn to navigate comfortably and confidently:

You will relax and enjoy yourself far more when on a guided scuba dive - including better air usage!

If you know where you are at any time on a dive, and you know where the exit point is, you will find you relax far, far more and really enjoy your time underwater.

The added bonus of having the freedom to dive independently (see our blog Can I dive independently?) should be seen as a secondary and, largely, unnecessary pressure for most divers.

Scuba diving has to be 2 things - it has to be fun and it has to be safe. Being able to navigate helps make it both.

Trust the compass

Our number 1 tip would be to trust the compass. And our second tip would be to trust the compass, before always referring back to our number 1 tip (just in case there is any doubt).

Third tip is simply: trust the compass.

We have absolutely been on dives where we are convinced something is wrong with the compass. Nothing looks familiar, the timings seem off, the direction ‘feels’ wrong but then, just as you are certain that you need to change something - hey presto - your exit or pilot point appears, as if by magic.

The compass will not lie to you. Your brain can and often will.

Things change under the water - magnetic north doesn’t!

Note: Remember that there is a difference between a northern hemisphere and southern hemisphere compass (or compassessesssss as we say here at Dive Bunnies HQ). You can get duel hemisphere compassessesssss.

And one key question is - if you decide that the compass is leading you astray, then how do you decide which direction to head in instead? Guess?  

It is counter intuitive to follow a compass when every fibre of your body is screaming that it is wrong... but believe us… follow the compass.

Aim to Miss

Currents affect your position. 

Whilst true north never changes, the current will affect where you are, relative to true north… so if you move, your position relative to true north also moves.

We are not getting into compass technicalities in this blog, but this does affect your bearing.

So a top tip is to aim to miss. 

If you are looking for something in the blue like a wreck or a  large sea fern, think about which way the current is pushing you, and then aim to miss your target. You should aim to miss 'up' current so that the current will help 'push' you onto your target.

You must know how long it should take you to reach your intended target, so when you reach the time limit, if you can't see your target, you know it must be down current from you.

You need to think about the strength of the current but the below illustrates what we mean - aim to miss, and then drift to your target.

Although only illustrative, Fig.1 shows the likely changing bearings (green, purple and yellow) as a diver progresses through a dive, pushed by the current and aiming directly for a target.

Fig.2 shows how the bearing can stay the same if you aim to miss from the outset. 

Pilot points

These go hand in hand with your compass. 

A pilot point is any underwater feature that you can use to pinpoint your location on a scuba dive and take as a reference for a compass bearing. Some scuba dives can be navigated by pilot points alone - although we always recommend a compass so you can turn directly towards shore at any time.

They could be coral, rock or sand formations or sunken objects such as wrecks, girders or debris.

You can, as an exception, use territorial marine life - but it is far from ideal - animals have a habit of moving!

The important consideration is to make sure that your pilot points are unique and memorable… choosing a huge brain coral is great, unless there is another one further along the reef.

Rock formations are ideal, but remember to look back at them as they will look completely different when you approach from the reverse angle.

Ideally you want 3 'associated' pilot points and give them stupid, memorable names. One site we visit has a pilot point that is 'Darth Vader eating Medusa's tail' due to the way that 3 prominent corals lay relative to each other.

It doesn’t then matter that one of those corals is a huge brain coral, because it is the only brain coral that is eating Medusa's tail when viewed in our own, warped way!

Another vital thing to note is the depth at which your pilot point is located. Clocking a rock formation at 14m (46 ft) is pretty useless if you then pass it at 26m (85 ft) on your way back!

Also, if your target is at 30m (100 ft) then you won’t see it at 20m (66 ft) if viz is only 8m (26 ft).

Time check

This is often of the essence in scuba diving and none more so than when navigating. 

Time is a great indicator of when you should be ‘expecting’ to see a target or a pilot point (and therefore what depth you should be at in order to see it) and also a really good indicator if you have got things a bit wrong.

That is where a good briefing and a bit of bravery comes in. Be brave enough to acknowledge you’re off course and turn back.

Always give yourself a cut off time when navigating a scuba dive. 

A typical briefing for us would be “When we leave the reef we should see the wreck after around 7 minutes, if we don’t then I will keep going until 9 minutes, but then turn back to the reef as I’ve clearly missed it”

Remember, one of the aspects you need to again factor in to your navigation is current and consider the timings relative to if you are diving into or with a current.  It is totally arbitrary and a judgement call.

Unexpected current - change your plan

Once you have set your plan, never, never be afraid to alter it - on the hoof.

  • If you have a diver that is less comfortable than expected - change the dive plan.
  • If you have more boat activity than expected - change the dive plan.
  • If the current is moving in an unexpected direction or is stronger than expected - change the dive plan.

Current is one of the great unknowns in scuba diving. Although there are lots of signs that you can see from the surface (including asking exiting divers!) you never really know until you are in the water.   

If the current doesn't fit your plan, then you need to change your plan. You can't change the current!

Have an agreed sign for current so you can let your buddy or any other scuba divers know and then revise your plan. Always start your dive diving into the current.

Even if the current is in the direction that you expect, it may not be what you expect. If it is stronger than you anticipated then you may need to think about staying deeper longer, or coming up earlier so you can ride the current back to your exit.

Again, it is a judgement call. But make the call early...no-one wants to be swimming hard back to an exit. 

And don’t get unnecessarily hung up on how close you get back to the exit. Provided you surface close enough to, and up current from where you need to be then it’s all good.

And anyone diving with you will simply assume that you surfaced where you wanted to regardless!

The real magic of real navigation

There are no secret teachings - nothing that grasshopper can impart to the young scuba Padawan or anything like that.

But if there was, it would be this:

Navigating a scuba dive is about knowing you are navigating a scuba dive.

It is not a dark art. It is not especially difficult or challenging. Those of us who happily do it are not scuba gurus. 

Most of the guys and girls that we speak to think it is a huge mystery, simply because they enjoy their guided dives. Looking at the marine life and the topography, snapping photos and generally having fun under the water is what they are focused on, not navigating.

If they chose to navigate they would concentrate far more on the compass and the pilot points, the timing and the depth...and navigation starts to happen as if by magic. The underwater environment can be extremely simple when you actually look at it.

Some insight from the author about the first guide he ever guided...

“I was a Divemaster candidate and this was at a site called The Labyrinth. I can remember specifically saying that it was the one site I did not want to guide. 

For me the clue was in the name. It was a fascinating site, but one that had twists and turns, depth changes and rock falls, all of which were intricate and fascinating, but it was not an easy place to keep your bearings around.

So naturally my instructor chose this site. Thankfully he didn’t tell me the day before so I was at least able to sleep that night! 

But he did so for a very good reason - which was to demonstrate an overarching principle of 'Keep it Simple' - the very art of looking for simplicity in a sea of, apparent, complexity.

Yes the Labyrinth appeared to be an underwater maze, but in reality there were 2 big rocks, a gully and a gap. Keep your eye out for those and let the group indulge themselves in the apparent intricacies of the site.

It was still a genuine relief when the line came into view but what I had perceived as an extremely difficult site to navigate was, in fact, pleasantly straight forward”

But be warned. Once you start to navigate a dive, always a navigator you will be. Join any guided dive and we will bet you a million Kit Kats that you'll also be navigating your way round!

The first step

An ideal place to start is to simply join a guided dive and navigate alongside the dive guide.

You don't need to be obvious in what you are doing or be part of the actual guiding. Just ask for their compass bearings and pilot points and sketch it out on a slate. 

The sketch doesn’t need to be a map of the dive site, just something basic that shows pilot points, the headings to and from those points, depths and which way is north.

Having north clearly marked allows you to know what heading to take at any point in the dive to head for home, if you need to.

Remember, the magic we discussed above - keep it simple.

We would then suggest your first navigation dive is at a site that you are familiar with. Take along a buddy or two who know what you are doing and are comfortable. It is then a great tip to dive that same, familiar site in reverse.

When you then decide it's time to drop in to you first, unfamiliar scuba site research, research, research. Know the currents, the usual conditions and ASK as a local dive centre for any top tips or things to be aware of.

And then...? Enjoy!

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