One of the divers who was diving with us the other day asked me a question which a lot of people seem to ask…
How do you do it, lead a dive and know exactly where you are going and know how to get back to the anchor…???
Well it made me want to write up this blog and give an overview of how we do it.
The main 2 things that you need when you are navigating a site is to know where you are and where you are going, to do this you need to have good observation skills and know how to use your compass. This is the aim of the PADI Underwater Navigation Specialty course. Those of you that have done your advanced will have had to do the Navigation part which touches on some of these basic skills.
Ok, so how do you improve your Navigation skills? There are many ways but here are some tips to get you started…
If there is a map of the site you are diving already then use it, try to remember the main landmarks mapped so that you know where you are, there may even be bearings…
Before starting your dive take a compass bearing of the shore, boat etc vs the direction of travel, this will get you out of trouble if you get lost.
Use natural Navigation, start looking as soon as you start your descent, for example, is the anchor near a landmark you can use, a rock or a wall that will guide you back… as you follow the dive site, make turns at landmarks that you can remember so that when you are on your way back you know where to turn. Another way of navigating is to pick a path that you follow such as a wall, a cut on a wall or special rock formation, look ahead and pick a point to aim to, you will need good visibility for this..
Go slow… not only will you miss a lot of what’s there to see but the faster you go the more you will get lost and you will not be able to take in the information of the route and landmarks.
Trust and use your compass… know how to use it and take it on every dive, I personally now use a digital compass built in on my suunto and it makes it so much easier. If you have a compass on your console then it is also now a lot smaller than they used to be and therefore easier to carry and use.
Stay away from sand only sites… most of the divers will end up going round in circles without a compass, if you have to go across sand, then my advise is to check the compass regularly to check you are still on track.
If you are comfortable with Navigation, Don’t be scared of exploring beyond the known sites but make sure that if you wonder outside of the dive site that you have information on currents, boat traffic etc…
Archimedes’ principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and it acts in the upward direction at the centre of mass of the displaced fluid.
So what does it mean? Why is buoyancy so important in the world of Scuba Diving? How can experienced divers make it look so easy?… well the truth of the matter is that knowing the principle of Archimedes or trying to figure it all out on this blog is not the answer… the answer is simply practice, experience and adjust.. I always tell divers that it takes someone on average between 50 to 100 dives to be comfortable in the water and have very good buoyancy skills. In this blog I will talk about ways to improve buoyancy and what to look for to adjust your trim but everyone is different and what works for one person might not work for another, therefore if it works then use it, if it doesn’t then try something different..
One of the first things you should look at is how you are positioned in the water, the majority of divers will be head up position, fins kicking upwards, kicking all the sand up… this is normal for beginners but it is something that should be looked at and fixed at the beginner courses such as the Open Water course. Unfortunately most of the time it is due to the Instructor over weighting the students to keep them down in case of an uncontrolled ascent and not adjusting as they progress… the diver then thinks it is normal and carries on using the same amount of weight once qualified.
All this extra weight will change our centre of gravity… COG.. those into car racing or flying will know that it is very important to understand and monitor the COG, well in diving it is the same, the more weight you carry on the belt (below the centre of gravity), the more air compensation you need therefore the BCD is inflated which increases the air volume above the centre of gravity, this will cause the top part of the body to float upwards and the fins to lower.
Most divers will notice this when they stop fining such as on a safety stop or taking a photo. When moving forwards they are constantly finning upwards therefore compensating for the negative buoyancy and being able to hold their depth somewhat, but when they stop fining they sink.
Another area to look at is how horizontal you should be, my position is pretty much horizontal (flat) with my arms in front of me, and this plays two roles, 1 I don’t have to move to monitor my computers and 2 it adds weight to the top of my COG. If I was to bring my head up it would also cause more friction against my body when trying to move forward, To demonstrate the effect simply put your hand outside your car window when moving and hold it horizontal/flat, it would be streamlined but when you slightly rise your fingers your hand will be pushed upwards…
Try to practice swimming in a skydiver position where your shoulders are inline with your hips and your back slightly arched. Once you start to get into this position you will soon realise which part you will need to adjust.
Weight belt or integrated?? “Maybe Both”!! The best way to adjust is to have smaller weights making up your total weight needed, 1kg or 2kg at maximum.. There are so many options for weights and as previously mentioned it will be different for everyone. Some of the options are, harness system, integrated weight pouches, weight belt, tank weights, BCD trim weight pockets, ankle weights, clipped weights (these are good for trying out different positions).
So imagine I have a diver who has all their weight on their belt and they are complaining of not being able to keep their legs up… my first question would be, are they properly weighted?, first step is to do a weight check with an empty tank 50 to 60 bar of air. Once that is checked then we would need to move some weight up, this can be done by using trim pockets or tank weights. Another option which we haven’t discussed yet is the tank position, moving the tank up would increase the weight above the COG therefore bringing the upper body down and more horizontal.
Distribute your weight as much as you can and try out different positions and configurations, if it feels good then use that configuration for a while then adjust if required.
As well as adjusting your position and weights we need to look at how we use our breathing and BCD inflator.. Too many times have I seen divers with their inflators in their hands inflating and deflating as they navigate through boulders, rocks and walls… only to find out that they have to turn back to the exit 15 minutes before anyone else… if this is you, your air consumption could be affected by how much you use your inflator or how much weight you are carrying.
Without holding your breath at any time you should be able to use your breathing control to move vertically in the water. On small depth changes breathing a bit deeper or releasing that extra air from your lungs could move you over a boulder or to descend to a sloping bottom, this will reduce the amount of air you use in your BCD and reduce air consumption, for big depth changes you would of course still use your BCD. Log your configuration
For those that dive regularly with the same equipment it is easy to keep a note on your mind as to what weights and where you position them once you have done all your testing and check out dives… for some of us that use different kit and/or dive in different environments we cannot remember all the details… this is where a log book comes in handy… many divers ask me.. surely you don’t keep a log book still after thousands of dives… the answer is yes I do, I can give you the hours I’ve spent underwater and how many pleasure dives and courses I have done and there are various reasons why I still log them (through my computer download) but for the topic we are discussing I log configuration details and weight used such as for sidemount, twinset, single cylinder, single cylinder with a stage bottle or when I use a shorty vs a 5mm wetsuit or 7mm semidry.. each with different weight position and amount.
If you select not to keep a log book then simply note it down on a booklet and keep it with your dive gear, it saves time, money and embarrassment… after all you don’t want to be the one on the surface with your fins sticking out of the water trying to fin down to start your descent…
I hope this has given you some guide around ways of improving your buoyancy, and if you need more help and guidance get yourself on a Peak Performance Buoyancy course… we run them all the time and most divers come out of the course with carrying less weights and better air consumption..
Always seen divers cruising along effortlessly like they were part of the environment, wish you could do the same, check out our 5 tips to better Buoyancy, test them out on your next Scuba dive.
Being weighted correctly is essential for good buoyancy, on your next dive do a weight check before you exit, see exactly how much you need to submerge, use 1kg and 1/2kg blocks/pouches to get it right – don’t forget to breathe out to descend. Spread your weights out and don’t forget when you change equipment such as Cylinder or suit you also may need to adjust weight.
Little by little is the key, make yourself negatively buoyant then add small amounts of air while breathing be patient it may take a few seconds after you add air to start to rise. After you have it set small depth change shouldn’t make a big difference – don’t keep adjusting if you don’t need to.
To let air out of the BCD use the most logical dump, you will have several, normally at least one button with the inflate button, one at the end of the inflator hose which you pull to use, a shoulder dump and a rear dump – depending on your position in the water use the one highest on the body. Be familiar with all your dump valves how to use them ad where they are so you can instinctively dump air if required.
A big problem a lot of people experience with buoyancy is due to incorrect position of weight, spread the weights out many BCDs have trim pockets and integrated systems use them wisely.
Don’t wear your weights too far back especially women, try to get the weight over your hips to help balance out the weight of the cylinder on your back. I recommend 50% of your weight on a belt and 50% in your BCD favouring more weight on the BCD than the belt.
Try ankle weights, they are not suitable for everyone but can help some with their position in the water.
Your lungs have a large capacity and breathing in and out is a lot like inflating and deflating a BCD, if you need to go over an object then try it by just taking a big breath, you shouldn’t need to add air to do this. In normal situations don’t breath too deeply you may find yourself having to dump air due to you just taking a really deep breath and beginning to ascend.
Remember before heading straight for your inflator try using your breath to control your position.
Practice, Practice, Practice
You have probably heard it 100s of times, practice makes perfect, with buoyancy it really counts, the more you do it easier it gets, challenge yourself on your next dive try using breath control to go over objects, practice with your buddy, take a 1kg weight and pass it to each other trying not to change depth. Make it fun and soon it will just come naturally and everything will just fit into place then you will spend more time enjoying the underwater word and less time worrying about controlling your buoyancy.
We get so many divers coming through our door saying how to improve their diving as they do not feel comfortable etc.. Well we have added some back to basics tips below which many divers forget about.. Some of this some of you would have not remembered from your Open Water courses and some of you will but this should be a good reminder for everyone.
1. Keep hydrated, especially in hot weather, at some point in your dive there will be strenuous activity, normally donning the equipment, with an exposure suit on it will cause a sweat (even in cold places) so its very important to keep drinking.
2. Equalize often- The first thing you are taught is about equalization, but with everything else going on (turtles above your head etc) many divers forget and realize too late, they then feel they can’t ascend back up to equalize when the rest of the group is going down. Often people give up quickly without giving it another try, if you have problems go up, signal to your buddy (Rattle or tank banger will help in these situations) and try to equalize again, don’t force it and descend slowly, if you are wearing a hood pull it away from your ears – keep equalizing whilst descending. The most important is to not feel pressurized to carry on the dive if you are having equalization problems.. There will be another day and another dive which is better that the alternative.
3. Breathe – Again one of the first things we all learn but over time good breathing techniques can be lost, and we may skip breathe, or breathe shallower, this can lead to an increase build up in carbon dioxide which leads to headaches and could even cause blackouts. There are better ways of conserving air such as, improving your fitness, staying shallower, taking notice of your breathing, improving your weights and trim, keeping warm, breathe deeply & slowly from the diaphragm and exhale fully.
4. Take it Easy – We don’t scuba dive to try and get somewhere
quickly, there is no underwater race, we are all there to enjoy what we see underwater. There is no point in rushing, take your time, look under the rocks, enjoy what is there – don’t just swim past and wonder why you are exhausted at the end of the dive. A good sign of you finning too fast is if after the dive you are wondering why you didn’t see that Arrow head crab, that cuttlefish hiding next to the rock etc.. If this is you, think about it next time you dive and you will find it is a better experience for you and your buddy.
5. Trim – Having your weights and cylinder in the wrong place can make a dive very uncomfortable, it just doesn’t feel right, everything is an effort and you use a lot more air trying to get it right underwater. This is where spending time in the pool adjusting your weights come in handy, in fact, PADI has picked up on this and built trim into the revision of the open water course as it is so important. Perfecting trim comes with experience, but the best thing to do is to get your buddy to look at you or even take a picture, you will then be able to see what is wrong. The PADI PPB course is all about looking at Buoyancy and Trim so its a great course for helping and getting tips to getting it right.
There are lots of other tips available to improve your diving, these are just some of the main ones and what we believe helps a lot of our divers..