All of us who enjoy the sea have a doubt before going to our chosen place.
What will the conditions be like for diving?
That doubt has an easy solution if you know “interpret” the predictions.
Here you have everything you need to know to interpret in advance the conditions and state of the sea at your diving site, but remember that before getting into the water you must evaluate these conditions yourself for at least 10 minutes.
There are 5 factors to consider.
We will not talk about surface time, nor temperature. Although it may be of some importance, in these cases we will simply have to look at any weather forecast app.
1 – WAVES
What is it?
A wave of water on the surface that generally gains strength with the wind. and size until the depth is less than its height and it begins to break.
How does it affect?
This is possibly the main factor that determines whether we can dive or not, as it directly affects the ability to enter and exit the water.
How to measure it?
Knowing the address, the height and the period.
Address:
We will be able to see the direction of the wave with an arrow that will always indicate where it is going, and always and when the wave is not heading to our area chosen for diving, it will not affect us.
For example, if in our chosen app we see that the arrow is pointing downwards, it means that the best conditions will be in the south.
You will be able to see it in your app (Windguru) and it will show you the height of the waves in meters, you must take into account the 2 waves that you will see in the app as wave 1 and wave 2.
Height:
The maximum depth at which you can dive depends largely on the direction of the dive, the diver and the environment., always assuming that the direction of the wave will make it break at our chosen spot. Remember that otherwise we can assume that the coast will be calm.
0.7m > Small:
As long as the wave height is below 0.7m, we could consider them as small waves.
0.8m/1.3m Medium:
From 0.8m to 1.3m we would enter medium waves, which in some places will allow us to dive easily and in others will make it more difficult.
1.4m/1.8m Big:
From 1.4m to 1.8m we could classify them as big waves, these waves will prevent us from diving in most places where the entrance is from the coast and will make things more difficult for us from the boat.
However, there are places where you can dive with these waves.
1.9m < Very large:
Whenever the wave height exceeds 1.9m, we are talking about very big waves and, with a few exceptions, it would be best not to plan our dive on those days.
2 – PERIOD
What is it?
It is the time in seconds between wave and wave.
How does it affect?
In 2 factors: 1st The swell, 2nd The overflow or drag
1st Swell:
It's that swaying that we feel when we are submerged.
2nd Drag or Overflow:
The foam caused by a broken wave that moves us on the surface.
You will notice it more in reverse with depth, The shallower the area, the more we will notice its effects.
It will affect us in several phases of the immersion: Entry/Exit, Submerged.
When entering/exiting we will have to be very aware of the time we will have between series and series (exceptionally large waves that are followed by a period of calm) to leave alone at that moment.
When we are submerged, we will have to try to spend as little time as possible in shallow areas, paying special attention to those areas where there is marine life that we could harm or an orography that we could hit, cut, or get entangled in...
How to measure it?
You will be able to see it in your chosen app (Windguru) and will indicate the period with a number that will measure its “strength”.
5> Low:
If the period is below 5, We will likely have a low swell and we will be able to dive without taking this factor into account.
6/8 Medium:
From 6 to 8, we could consider it a medium swell and in areas below 5m we will have to take into account the appearance of swell.
9/11 High:
From 9 to 11, we can consider it high, and the swell may appear at greater depth.
12< Very high:
Combined with a big wave, it will be a good day for surfing, but dangerous for diving.
We must take into account that the size and direction of the wave will have an influence.
3 – CURRENT
What is it?
Let's say they are movements of water within the sea.
How does it affect?
It affects us in many ways, but we will mainly talk about displacement and marine life because they are the most important.
Displacement:
In those diving sites where the current tends to push you away, we should only dive on days and at times when there is likely to be no current.
As for movement, if we use them to our advantage we can travel long distances, but otherwise we could become tired.
For this reason, it is always advisable to start against the current and return with the current when diving back and forth.
We must also remember that if we are caught in a current, generally the best way to get out of the current is to move to one side to get out of it, and never to swim forward.
Marine life:
In many diving spots the current is a factor that will change marine life.
Especially in places where there are species that feed on the nutrients they carry. These species tend to attract predators and are usually easier to observe.
How to measure it?
First we must know if there is usually a current in the area or not, and for this it is always best to ask the professionals who dive in the chosen area.
In this case we will not be sure what we will find until we are submerged.
But there are two factors that we can “read” beforehand to get an idea of what the conditions will be. These factors are the coefficient and the tide.
Coefficient:
You will be able to see it in your chosen app (Windguru) and will tell you whether the tide is “big” or “small”.
A very high coefficient means that the tide is “large,” and therefore, as there is greater movement of water, more currents are probably generated.
50> Low
50/70 Medium
70/90 High
90< Very high
Tide:
If you want to dive without current, the best time of day will be right during the breakers.
High and low rallies are the moments when the tide has reached its limit and turns.
If, for example, we want to dive in a place with strong currents, the ideal would be to be in the water half an hour before the surge and leave half an hour later.
If we add to this a low coefficient, our chances of success increase considerably.
4 – WIND
What is it?
It is an air current and the main factor that creates waves.
How does it affect?
Wave creator, we already talked about waves before so we will focus mainly on the following points: 1st Ability to move on the surface, 2nd Increased stress on the surface, 3rd Boat navigation.
1st Ability to move on the surface:
Depending on the speed and direction of the wind, on certain dives, it can take us away from the chosen dive site. It can also sometimes take us to dangerous areas such as surf zones or areas with currents.
2nd Increase in surface stress:
Stress can be caused by several factors, but the most common are exhaustion or difficulty breathing on the surface.
Fatigue: If we do not dive quickly, the diver may become exhausted and start the dive with a high heart/respiratory rate. This can “facilitate” the appearance of problems caused by stress.
Difficulty breathing on the surface: If we are positioned facing or laterally to the direction of the small waves generated by the wind, the water that splashes into our mouth can make it difficult for us to breathe normally.
The easiest and safest option is to carry a snorkel or wear a regulator to avoid this problem. Another option is to position ourselves with our back to the direction of the small waves generated by the wind.
3rd Navigation in a small boat:
If we are sailing against the wind towards our diving point and the wind is fast enough, water will enter the deck during the entire journey.
How to measure it?
Wind is usually measured in knots, but like waves, another determining factor is its direction.
Another important fact is that, unlike what happens with waves, even if the wind comes from land, it will be a determining factor for the conditions we will find at the diving site.
If the wind is blowing from the open sea towards our entrance, we will have to anticipate that we will encounter waves that will move us towards the breaking zone.
If, on the other hand, the wind comes from land and moves away towards the open sea, we will have to count on the fact that said wind will move us away from the coast.
That said, let's assess how to measure it:
You will be able to see it in your chosen app (Windguru) and will tell you the speed and direction of the wind.
9 > knots Low:
If the wind is below 9 knots it is most likely not a determining factor.
10 to 18 knots Medium:
In this range, in some places and in a certain direction, it can be a factor to take into account, especially when diving from the shore.
19 to 28 knots High:
At this speed and in a given direction, the wind will certainly be a factor to take into account.
28 < knots Very high:
Unless you know the place very well and are sure how to handle these conditions, it is best to look for another more friendly location to dive.
5 – VISIBILITY
What is it?
The distance you can see while submerged on a dive.
How does it affect?
Above all, it will affect us mainly in 3 factors:
1st Do not lose our partner:
In low visibility conditions, it is highly recommended to increase our efforts to be able to see our partner at all times. This way we will ensure that we are not alone at any time during the dive.
2º Find the way back to the exit:
If visibility is poor, returning to the exit point can be a difficult task. It is therefore advisable to pre-establish a reciprocal course with the compass before starting the dive and not venture beyond the diving sites. that we know in depth.
3rd Ease/difficulty of sighting the animals or objects we want to see during our dive:
Obviously, the lower the visibility, the more difficult it is to spot our target. It is advisable to focus on species that live on rocks or the bottom to make it easier to spot them.
On the other hand, in places where predators abound, we will have a better chance of seeing them up close.
How to measure it?
Visibility is a subjective factor that varies greatly depending on the location.
For example, in the more than 12 dives that we can do in the Sardina de Norte Bay, which is located in the Municipality of Gáldar in Gran Canaria (one of the 10 best diving sites in Spain), these would be the ranges to measure visibility.
10> Bad
11 to 15 Average
16 to 25 Good
25< Very good
Below we will list certain factors that influence visibility. But to find out the visibility conditions at the diving site, it is best to ask someone who has dived before.
State of the Tide:
In places where there are ports or relatively still water nearby, visibility tends to be reduced when the tide goes out. This is because the relatively still water flows out to the open sea.
Current:
Usually, in places where there is more current, visibility tends to be better. However, this is not the case everywhere.
Swell:
If there is a swell, it will move the substrate on the bottom and raise it, making visibility worse.
Sunshine:
On a clear day, when the Sun is at its highest point, visibility is greater than when it is cloudy or its position is closer to the horizon.
Rain:
If large amounts of water reach the sea from land, they carry mud and other components that will reduce visibility for days or even weeks.
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