Wednesday, September 21, 2011

A Day of Diving

After surfacing.  In the back ground: The Ann-Lise 3 and the Davao Dive Crew.
We finished our Advanced SCUBA dive training off of the coast of Samal island in southern Mindanao. The water was clam and the sun shined as we floated lazily across the channel on the Ann-Lise 3. Three dives were planned to wrap up our advanced certification.The first dive of the day was a "deep dive", a dive exceeding 25m, 82ft.  We plunged into the blue, quickly having more water above us than ever before. It was an uneventful dive, if there can be any such thing. We observed fish and swam about. Colors all fade. Red is washed out before 20ft followed by orange, yellow and green. Below 70ft everything, corals, and fish are all shades of blue and purple. Decompression sickness or "the bends" is a factor to account for when diving at these depths. It occurs because the nitrogen that is mixed with the oxygen in your air tank gets forced into the cells of your skin tissue over the duration of the dive. At 30m the pressure is 4x greater than on the surface. What this means is that if you stay down too long, or ascend too quickly, not allowing enough time for the nitrogen to leave your cells and be exhaled, it expands to 4x it's volume. This Hurts! One can imagine having intense internal pain under your skin from these expanding bubbles. Don't worry it didn't happen to us. Using a simple table to factor depth and time we can plan dives to avoid this painful experience. We ascended casually to the boat and ate lunch.
At 25m, 82ft below the surface.

The second dive was a search and recovery dive. This dive is used for finding lost items, a pair of keys, for example, that have been dropped over board. Using a compass we navigated a couple different search patterns. One was an expanding spiral and the other an alternating "U" search pattern. It was damn difficult too, with the current constantly pushing us sideways off of our line of direction. It takes a lot of practice to be anything more than awful at navigating underwater. We had to first review navigation above water before we had any chance at being successful below. We also practiced swimming at mid level in the water. With no line of reference, too far from the bottom and too far from the surface, it's very easy to become disorientated. There's nothing to judge your speed or direction, only limitless blue. If it weren't for the bubbles you wouldn't know up from down. With air running low, back up to the boat we went.

Cozette with her new snorkel and goggles.
Our final dive as students was a night dive! The sun fell into the water and we began to follow its example. We prepared our dive torches, attached extra lights to our gear and suited up. nervously we descended into the black water. Down, down, down, only blackness until the bottom. The Corals open up more at night, some fanning out into the surrounding water. Despite the depth, colors appeared vividly bright in the light of our torches, punctuated by the contrast of the dark water. Most fish were hidden away in their cracks and crevices to escape nocturnal predators like octopus. Some fish were active though, kinds you can only see at night, the "second act", as our divemaster put it. The darkness added a certain mysteriousness and an eerie, alien-like feeling to the sea floor. I felt like I was exploring the surface of a distant planet, expecting to see some unrecognizable creature come floating towards me out of the darkness. A twinge of claustrophobia is felt from the encasing blackness in all directions, similar to what I have felt only inside of a cave. We covered our lights and enjoyed the show, millions of bio-luminescent plankton flashed sparks of green in the water around us, The lightning bugs of the sea. Just as the current began to get very strong, we found the boat's anchor line and ascended one final time as dive students. Aboard and exhausted from the long day, we drank hot coffee and cruised back to the port and home. Food, shower, sleep and dreams of future diving.

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