Following the article Training Fundamentals: Taking Your PADI Advanced Open Water Course at Scuba Diver Life
You shall become an AOWD, if:
- You want to increase your depth limits,
- You would like to convert into someone who “thinks like a diver.”
- You would like to take part on any dive safaris worldwide
- You Are interested in specialties as: in the Deep and Underwater Navigation (mandatory requirements) + three elective Adventure Dives, as buoyancy and finning skills, night dive, boat dive, or fish identification.
These individual Adventure Dives completed within the AOW course offer credit toward the full specialty diver certificate for that particular area.
The full list of eligible specialties is available at padi.com.
What the new, “thinking like a diver” training means:
careful planning of dive objectives, planning depth, time and gas turn-points, situational awareness, managing task loading and practicing good habits above and below the surface.
Turtle-sightings in November
Your child knows how to swim and is comfortable in water, and of course, has the parental approval… She or he does not need more to start with the SCUBA course program.
Children can start their Junior Open Water Diver course from the age of 10. Students 10 years old and up can utilize the online eLearning program. Younger students (under 13) shall learn from the PADI Open Water manual and DVD.
After being certified, there are still some restrictions:
- Divers 10-11 years old must dive with a PADI Professional or a certified parent or guardian, and dives cannot exceed 12 meters/40 feet.
- Divers 12-14 years old must dive with a certified adult and dives cannot exceed 18 meters / 60 feet.
Certified Junior open water divers 12 years and older can continue with the following courses, in order. In these courses, dives may reach a max depth of 21 meters / 70 feet.
- Junior Advanced Open Water: Ages 12-14
- Junior Rescue: Ages 12-14
- Junior Master Scuba Diver: Ages 12-14
After the age of 15, the same regulation applies as for the PADI Open Water.
Studies say, that birds avoid to crash with other birds in air by always turning right, or in some cases changing altitude. This could be useful for unmanned aircrafts and autopilot systems also, so the increasing air traffic would not cause disturbance.
September was loud of the sea turtle nesting season, and at the end of October we shall see the “results”, emerging from the sandbed.
In below picture a hawksbill turtle is nesting (the third time in this season) nearby a visitor shelter.
Below close-up shows a giant bronze gecko feeding on the bait, used for capturing them during an SIF scientific project. The sightings and number of captures help the researchers to estimate the size of the population.
Source: SIF FB
In the ScubaDiversLife new blog post serie, John Keen, PADI Master Instructor presents short stories, describing the main mistakes, resulting in poor air consumption while diving, and most importantly, leads us to the way how to solve them.
The use of 15l tank is not the correct answer to compensate for poor air consumption, as using a bigger tank is similar as to rely on an airbag, says the author. “Somewhere along the line you’ve missed some training or not developed the skills and techniques that will allow you to log longer bottom times”. Big tanks also create more weight, discomfort, extra workload.
Good buoyancy is the key to lowering the air consumption. It takes less time to teach good buoyancy control than it does to deal with the negative consequences of its absence.
The main ingredients of good buoyancy control are:
- correct weighting,
- mastery of your BCD, and
- good trim in the water
The Right Weight
Proper weighting provides maximum control and comfort underwater. Diver with too much or too little weight will be trying to correct the situation during the entire dive, and will consume more air.
In general, the correct amount of weight is guesswork. The best way is probably to get in the water and figure it out by trial and error with the guidance of the dive master.
With weights on, feet still and an empty BCD, you should remain at the surface only via the air in your lungs. The manual says that if the water reaches eye-level or around the forehead, you’re weighted correctly.
To begin a dive, you must breathe out, empty your lungs and sink below the surface.
… and this is where the problems can begin. Many students can’t get down at all, and for some pros, the shortcut is to add more weight. This is as if the dive master would put a foot on the diver’s head to push him/her down.
Elsewhere in our manual, we learn that you’ll need about two pounds (one kilo) of lead to offset a liter of air. The average adult male has around six liters of air in his lungs at full capacity. If he breathes out before descending, then together with proper weighting, he’ll drop comfortably below the surface. If the diver continues exhaling until his lungs are empty, he’ll develop a lung squeeze with increasing depth pressure. Conversely, if he barely drops a few inches and then takes a great inhalation, filling his lungs to the brim, then he’ll rise back to the surface. This is when many divers tell their guides they need more weight, not realizing that they’re about to burden themselves with unnecessary lead.
By deflating and exhaling you begin your descent. If you take very small inhalations between the surface and 10 feet (3 m), you’ll avoid a squeeze in the lungs. Below that depth, physics takes over and allows you to swim freely, breathing in and out at full volume.
The reason for this, that tiny bubbles in the neoprene wetsuits will compress at about 10 feet (3 m), and this reduces the positively buoyant characteristics we experience on the surface.
However a diver who is underweighted might still descend, when their tank becomes lighter, will suffer. Some signs: the diver turns upside down and fins until the deeper water compensates for the lack of lead. Taking short, shallow breaths to avoid filling their lungs and rising upwards. This is dangerous, however, because the diver no longer gets a full intake of air to properly oxygenate the circulatory system during the all-important off-gassing process. The extra exertion of trying to stay down will also increase air consumption and shorten the dive. This of course is the opposite of the intended effect of carrying less weight.
The BCD mastery
Finning is energy consuming. You may not even realize it, but you will use up a little more energy, with a small increase in your breathing rate according to the increasing the workload.
Stop, cross your arms and legs and wait. A slightly negative diver will slightly drop. The answer isn’t to start kick your way back up, than your extrenal and in-built BCD: the jacket and your lungs.
Pumping several liters of air into your jacket on the way down means that it’s bursting to get out on the way back up. Many divers get caught out from 40 to 20 feet (12 and 6 m) where the pressure-differential is the greatest. What worked between 60 and 40 feet (18 and 12 m) will not slow your ascent in shallower water, where jacket expansion is exponentially greater.
Weight placement and trim
The best placement of lead weights is higher up on the diver’s body in rear shoulder-mounted pockets, but it is key to not have too many weights in these secondary locations; as it is necessary to dump enough lead quickly in an emergency situation.
Splitting the location of a diver’s weights will help them to maintain a horizontal trim. More streamlined we are, the less resistance there will be and the more efficient we will become: will breathe much more efficiently and increase our bottom times.
This requires all three ingredients of good buoyancy control:
- proper weighting and positioning of those weights;
- proper use of the inflate/deflate controls of your BCD to remain neutrally buoyant; and
- horizontal position in mid-water.