Dive #2: Pasir Panjang House Reef
Date: 25 August 2006
Day: Friday
Time: 10:55 (GMT +8:00)
Location: Redang Island Malaysia
Duration: 0:43
Cumulative Time: 1:29
Max Depth: 11.2 meters
Sky: Clear
Waters: Calm
Visibility: 10 meters
Bottom Temp: 29 ºC
Starting Air: 3,000psi
Ending Air: 1,250psi
Surface Interval: N/A
Starting Pressure Group: N/A
Ending Pressure Group: J
Dive Buddy: Soon Yean
Dive Master: None
Another shore dive so again we had to go through the tiresome hike down the beach to point of entry. Once again struggled to get into my fins without falling over while fully geared. This dive also required us to finish up with some of the basic safety skills as per PADI syllabus. Fortunately we covered most of it during the first dive.
At a depth of about 7 meters, we took turns to exercise CESA (controlled emergency swimming ascent) to the surface. The concept is simple - in the unlikely event that we find ourselves out of air at a depth no deeper than 18 meters, and our buddy is not near enough for us to use his/her alternate air source, we basically just take one last deep breath from our regulator and start a slow swim up to the surface.
Yes, 18 meters is quite deep, so how do you get to the surface on just one breath of air? The science behind it is that the air in the lungs under pressure will slowly expand again when the pressure drops as we ascend. So as we swim up, more air in our lungs becomes available. And the end result it that we quite possibly still have a full breath once we reach the surface even though we release a stream of air bubbles as we ascend. This is good to know so that we don't panic if we run out of air.
Our neutral buoyancy skills were also tested here. This is a slightly tougher exercise because we have to 'hover' in mid water by keeping our body and gear neutrally buoyant. That means that you don't float up to the surface, nor sink to the bottom unless you choose to. Once you have just enough air in your BC, you can actually control your ascend/descend motions by simply breathing in and out. Take a deep breath and you float up; release all the air in your lungs and you sink. A slower, shallower breathing rate keeps you hovering.
Buoyancy control is especially important because when reef diving, you want to be able to hover a few feet above marine life to avoid damaging the reef. Sometimes there just isn't any room for you to place your hands/feet. The other reason for having good hovering skills is whenever we dive at a depth greater than 10 meters, we're encouraged to do a 3 minute safety stop once we ascend to a depth of 5 meters. This is to release excess nitrogen from our blood (it gets in our blood when we breath compressed air while the body is under pressure). So you can imagine that it's not easy to keep your body at a depth of 5 meters for 3 whole minutes.
The usual marine life was there to keep us company. Chewy picked up a cushion star and a species of sea cucumber for us to have a closer look. Both harmless of course... and yes, we left them as they were before moving on. Also seen in the distance was a giant grouper, approximately 1.5-2ft in size. We couldn't really make out what species because visibility was less than optimal, and lighting was quite poor too. It was more of a dark grey shadow than anything else. Quite slow-moving swimmer in my opinion, but it peacefully glided by without taking much notice of our presence.
After our second tour of the reef, we surfaced. Just before swimming back to shore, we had to do 2 last exercises for the books. The first was to remove and replace the weights while at the surface. No issue there. The last skill was much tougher, but less likely to be used - BC removal & replacement at surface. Removing the BC is a no-brainer... but it really takes some brains as well as finese to get it back on because it's the only thing keeping you afloat (your weights are still strapped around your waist, so you'll sink like a rock if you let go).
Day: Friday
Time: 10:55 (GMT +8:00)
Location: Redang Island Malaysia
Duration: 0:43
Cumulative Time: 1:29
Max Depth: 11.2 meters
Sky: Clear
Waters: Calm
Visibility: 10 meters
Bottom Temp: 29 ºC
Starting Air: 3,000psi
Ending Air: 1,250psi
Surface Interval: N/A
Starting Pressure Group: N/A
Ending Pressure Group: J
Dive Buddy: Soon Yean
Dive Master: None
Another shore dive so again we had to go through the tiresome hike down the beach to point of entry. Once again struggled to get into my fins without falling over while fully geared. This dive also required us to finish up with some of the basic safety skills as per PADI syllabus. Fortunately we covered most of it during the first dive.
At a depth of about 7 meters, we took turns to exercise CESA (controlled emergency swimming ascent) to the surface. The concept is simple - in the unlikely event that we find ourselves out of air at a depth no deeper than 18 meters, and our buddy is not near enough for us to use his/her alternate air source, we basically just take one last deep breath from our regulator and start a slow swim up to the surface.
Yes, 18 meters is quite deep, so how do you get to the surface on just one breath of air? The science behind it is that the air in the lungs under pressure will slowly expand again when the pressure drops as we ascend. So as we swim up, more air in our lungs becomes available. And the end result it that we quite possibly still have a full breath once we reach the surface even though we release a stream of air bubbles as we ascend. This is good to know so that we don't panic if we run out of air.
Our neutral buoyancy skills were also tested here. This is a slightly tougher exercise because we have to 'hover' in mid water by keeping our body and gear neutrally buoyant. That means that you don't float up to the surface, nor sink to the bottom unless you choose to. Once you have just enough air in your BC, you can actually control your ascend/descend motions by simply breathing in and out. Take a deep breath and you float up; release all the air in your lungs and you sink. A slower, shallower breathing rate keeps you hovering.
Buoyancy control is especially important because when reef diving, you want to be able to hover a few feet above marine life to avoid damaging the reef. Sometimes there just isn't any room for you to place your hands/feet. The other reason for having good hovering skills is whenever we dive at a depth greater than 10 meters, we're encouraged to do a 3 minute safety stop once we ascend to a depth of 5 meters. This is to release excess nitrogen from our blood (it gets in our blood when we breath compressed air while the body is under pressure). So you can imagine that it's not easy to keep your body at a depth of 5 meters for 3 whole minutes.
The usual marine life was there to keep us company. Chewy picked up a cushion star and a species of sea cucumber for us to have a closer look. Both harmless of course... and yes, we left them as they were before moving on. Also seen in the distance was a giant grouper, approximately 1.5-2ft in size. We couldn't really make out what species because visibility was less than optimal, and lighting was quite poor too. It was more of a dark grey shadow than anything else. Quite slow-moving swimmer in my opinion, but it peacefully glided by without taking much notice of our presence.
After our second tour of the reef, we surfaced. Just before swimming back to shore, we had to do 2 last exercises for the books. The first was to remove and replace the weights while at the surface. No issue there. The last skill was much tougher, but less likely to be used - BC removal & replacement at surface. Removing the BC is a no-brainer... but it really takes some brains as well as finese to get it back on because it's the only thing keeping you afloat (your weights are still strapped around your waist, so you'll sink like a rock if you let go).
posted by Mervyn at 6:23 AM
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