Friday, May 25, 2012

Chris' Dive Experiences: Pelagic Magic & The Manta Dive Kona, Hawaii (Part 2)


Courtesy of Lesley Alstrand
After the Pelagic Magic dive the night before, we were excited to finally do the dive that we had been hearing about for some time, the manta dive. We again met up at the dive shop for a briefing late in the day. We reviewed all the usual boat and dive safety stuff along with some rules for diving with mantas. The rules involved common sense stuff like don’t chase the mantas, but they also stressed not reaching out to touch the mantas. We were shown examples with photos and videos of how the mantas' protective mucus layer on their skin is damaged when they are touched, ridden, or scratched. Damage to this layer in turn causes rashes that take some time to disappear.

People are often mistaken to think that the mantas want to be touched because they come so close to you. What they are actually doing is trying to position themselves above you as your exhaust bubbles are floating up so that your bubbles hit their underside and roll up and off their belly. They enjoy this jacuzzi effect which simulates that sensation of being touched. This information was all new and interesting to me since I had often seen pictures of people touching and riding mantas in different places throughout the world.

At this point we were all ready to head out and get to see mantas for ourselves. The boat ride was very short and it turns out that the manta dive site is right next to the Kona airport. We signed up for two dives which including a daylight dive and then the manta dive. We geared up and descended. Our divemaster showed us the area where we would be later for the manta dive and then he proceeded to lead us on our daylight reef dive.

During our dive he showed us a razor fish who, when is scared and wants to hide, darts headfirst into the sand. We also saw a Hawaiian turkey fish which is endemic to the Hawaiian islands and looks like a miniature lion fish. On our way back to the anchor line toward the end of our dive, we saw two mantas on the edge of the reef.

During our surface interval we were assigned lights and briefed again on the manta dive. Mantas feed on plankton which are attracted to our underwater lights. So with the snorkelers shinning their assigned lights down in a tight area where the divers are, and the divers shinning their lights up where the snorkelers are, you get a super concentrated area of plankton. To further improve the situation for viewing, the divemasters also put two crates full of lights aiming toward the surface in the middle of the area where the divers set.

Finally the sun set and it was time to jump in! As we descended, we headed toward the beam of light that was shinning up from the two crates of lights. All the divers sat in a big circle. There were about 25 to 30 divers from 3 boats making up the circle. Once we settled in our spot, the show didn’t take long to start. It was amazing how much plankton was in the area; so thick you could see it bouncing off your light. And the area above the crates of lights was thick with plankton too.
All the lights from the divers pointing up mixed with the snorkelers' lights pointing down, making it seem like a Las Vegas light show you see on the strip. Only a minute or two passed before the first manta made a pass through the lights, right over the center of the circle, gulping up plankton. Before that manta even got out of sight there were two more back to back passing through the center of the circle and directly toward Lesley and I. They passed so close the first time I ducked my head swearing that they were going to hit me. Next, one came from behind me and right over my head. I could feel the water move right above my head as the manta passed on its way toward the center.

The next thing that happened I think really demonstrates how graceful mantas are. They started following each other and would do complete flips starting all the way from the crates of lights on the bottom and going all the way to the surface just below the snorkelers, upside down like aerobatic stunt planes. It was so cool to watch how graceful and precise they were. They would come within inches of both the divers and snorkelers but never touch them. This show went on for 45 minutes and then it was time to end the dive. I don’t think anybody wanted to leave this underwater show, but we had to.

On a funny note, during this dive Lesley and I both saw a moray eel that was very friendly.
He swam all over the place, checking out the divers and even sat between Lesley’s legs. After the dive, the divemasters let us know that this is the resident eel who always puts on his own show. The divemasters will follow him around and film the divers reacting both favorably and unfavorably to him climbing all over them. In our video we bought of the dive, the eel has his own chapter. It is hilarious to watch all of his shenanigans.

Here's a a nice video of the manta dive by med103:


Friday, May 18, 2012

Chris' Dive Experiences: Pelagic Magic & The Manta Dive Kona, Hawaii (Part 1)


Photo Courtesy of Leslie Alstrand
After a nice short flight from Lindbergh Field, we landed at Kona International Airport paved on top of a large old lava flow with the beautiful Pacific Ocean just below the runway. Kona’s airport is a throwback to how airports used to be and many tropical ones still are. It is open air with roof coverings to provide shade and a place to stay dry during a shower. Stepping out of the airplane onto the stairs instantly relaxes you as you feel the warm sun mixed with the fresh sea breeze and enjoy the view of the contrast between the lava fields and the blue of the Pacific Ocean. On this trip we were doing a dive that is well known and raved about “The Manta Dive” and a dive you hear about off and on but not too many divers do it “Pelagic Magic” dive.

First up would be the Pelagic Magic dive. We met at the shop for the dive briefing in the classroom a couple of hours prior to the trip departure. Lesley and I were being joined by 3 other divers; all of us were from southern California. This was the lengthiest dive briefing we had ever encountered to this point in our diving lives. The briefing included the usual boat safety info, a fish and creature id using both books and a video, but also had very unique briefings on the dive. The way the Pelagic Magic or black water dive is carried out is the boat drives a couple of miles out at sun down and stops when the ocean floor reaches depths of around 2,500 feet. Instead of an anchor the boat deploys a parachute underwater allowing it to drift at a slow smooth rate. Each diver is clipped to his own weighted line that is around 50 feet deep, allowing each diver to move up and down in the water column as he wishes.

After signing some paper work and being assigned some nice big LED lights, it was time to go dive. The boat's motor came to a stop and the deck lights came on as our DM called out that it was time to gear up. As we were finishing readying ourselves, the boat deck was a very busy place with diver rope lines being laid out and a huge parachute being deployed.

We huddled together for one last pre-dive briefing to make sure we were ready and to give us a couple of last minute tips. These included: “if you see a huge white thing toward the front of the boat that’s not moving, don’t have a heart attack it’s the parachute that we’re using”, “if you get freaked out, don’t be embarrassed, this dive isn’t everyone’s cup of tea and it happens all the time”, or “if you get cold, make your way up your line; after your safety stop, we’ll have a warm towel and hot chocolate waiting for you”, and last but not least “please don’t pee in your suits, that seems to attract our resident tiger and oceanic sharks”. "Ready to go?"

Lesley and I were both very excited mixed with a bit of nerves. We stepped up to the swim step one by one and were clipped onto to our rope. Lesley and I would be on one side of the boat and the three other divers on the other side; all spread out allowing us a lot of room to move around and not blind each other with our lights.

I did my giant stride off the boat. Dropping down into the the black abyss, I followed my line to the 50 foot mark. Soon after hitting that mark all the lights from the boat were turned off allowing all of our attention to be focused on what our flash light beams found. Because of the great amount of spacing between Lesley, I and all the other divers, each of us facing outward from the boat's hull, and because we were each at different depths, I only saw a brief flash of light now and then from the other divers. In fact, even though we were on the same side of the boat, I only saw Lesley once during our whole dive. 

While floating in 2,500 feet of water I was amazed bythe amount of life that moved by us during our 68 minute dive. During this dive I spied countless types of jellies and salps. Many of them defied logic as to how something living should look. And how they moved, some even unrolling themseleves from a ball to catch prey and feed, was just fascinating. All of this hapening while they put on a light show on a miniature scale in our light beams while they drifted by me on their hunt for zooplankton.

Toward the end of our dive a large school of Hawaiian reef squid came by using our lights to chase their prey. They seemed to check me out at a distance before disappearing again into the dark.

This dive showed me how vast the ocean is and how much life there is other then sharks in the pelagic zone. Although we didn’t get to see any sharks or a rare pelagic sea horse, we ended up seeing half of the species in the pelagic ID book that we looked at before the dive. This was a very unique dive that I had fun experiencing.

Experience the dive for yourself with this video from Jack's Diving Locker:

Friday, May 11, 2012

Creature Feature: Wobbegong (or Carpet Shark)

Wobbegong is the common name given to the 12 species of carpet sharks in the family Orectolobidae. They are found in shallow temperate and tropical waters of the western Pacific Ocean and eastern Indian Ocean, chiefly around Australia and Indonesia, although one species (the Japanese wobbegong, Orectolobus japonicus) occurs as far north as Japan. The word wobbegong is believed to come from an Australian Aboriginal language, meaning "shaggy beard", referring to the growths around the mouth of the shark of the western Pacific.

Wobbegongs are bottom-dwelling sharks and spend much of their time resting on the sea floor. Wobbegongs are well camouflaged with a symmetrical pattern of bold markings which resembles a carpet, hence the name "carpet shark". The camouflage is improved by the presence of small whiskers lobes[1] surrounding the wobbegong's jaw, which it uses to entice and catch fish. Wobbegongs are ambush predators. They use their relative invisibility to hide among rocks and catch smaller fish which swim too close. Most species have a maximum length of 4 feet or less, but the largest, the spotted wobbegong, Orectolobus maculatus, and banded wobbegong, O. halei, reach about nearly 10 feet in length.

Wobbegongs are generally not dangerous unless they are provoked. They have been known to bite people who accidentally step on them in shallow water; they may also bite scuba divers or snorkellers who poke or touch them, or who block their escape route. Wobbegongs are very flexible and can easily bite a hand that is holding on to their tail.[2]  They have many small but sharp teeth. Their bite can be severe, even through a wetsuit.  Wobbegongs have been known to hang on once they have inflicted their bite and can be very difficult to remove.[3] To avoid being bitten, divers should avoid contact.

Spotted wobbegong, Orectolobus maculatus,
showing the camouflage pattern and skin flaps
typical of wobbegongs.
Facts About Wobbegong Sharks
    They are so flat in their shape that they look like the part of the sea floor.
    They move slowly in water.

    Diet: lobster, crab & octopus
They normally are not dangerous, but there have been 23 confirmed attacks.

Normally, it is not an aggressive creature.
Attacks only when provoked.

The females of these species can deliver around 37 young at a time.




[1]^ "Wobbegongs - five species encountered in Queensland". Queensland Primary Industries and Fisheries. 2009-03-02. http://www.dpi.qld.gov.au/cps/rde/dpi/hs.xsl/28_12484_ENA_HTML.htm. Retrieved 2009-06-14.
[2]^ Kuiter, Rudie (1999). Guide to Sea Fishes of Australia (amended ed.). New Holland Publishers (Aust.) Pty Ltd. p. 12. ISBN 1-86436-091-7.

Friday, April 27, 2012

Chris' Dive Experiences: The Mythical So Cal Green Sea Turtle "Marine Room", La Jolla

Photo Courtesy of Virginia Hatter

Not all So Cal divers know that our temperate waters contain a couple of iconic animals. Animals that would normally conjure up thoughts of the warm, clear, tropical waters of the Caribbean and South Pacific. But there are a handful of lucky divers that have born witness to both Pacific seahorses and green sea turtles while diving here in San Diego. Lesley and I had heard a few stories over our 4 years of diving of divers seeing a green sea turtle, including Rod & Liz while diving at the Marine Room, but sightings remained extremely rare.

Our local dive site, The Marine Room, is named after the Marine Room restaurant sitting right on the beach, overlooking the ocean in La Jolla. Conditions at this site often vary more than other sites nearby primarily due to the coastal cliffs that surround it. During high tide, or if the surf is up a little, you’ll have waves not only rolling directly in toward the shore, but also waves cutting across as they bounce off the cliffs making it look like a big washing machine. The Marine Room offers two distinct dive options for a diver. You can kick out and to the left and enjoy rocky reefs with lots of life similar to diving La Jolla Cove, or you can kick straight out and catch the beginning of the same walls that you dive at La Jolla Shores.

Lesley and I awoke early on Friday the 13th to meet a group for a dive at Marine Room. When we arrived, we were greeted with clear skies, no surf and picture perfect surface conditions. We kicked out toward the rocky reefs on the left side of the dive site, enjoying the normal chit chat and joking that we had come to enjoy from this group of divers. Previously, Lesley and I had dove the Marine Room, but had always kicked out to dive the walls instead of the reef, so we were excited to see a new area and compare the two. We dropped down and kicked toward the kelp and reefs and I was amazed at how much life there was to see. We enjoyed loads of Calico bass, big and small, coming right up to our mask to check us out. Under almost all the rocky overhangs we found lobster peeking out at us waving their antennae. Spanish shawl nudibranchs and pipefish were found in and on the blades of eel grass. As we continued on we had a big school of jack smelt swim right in front of us.


Photo Courtesy of Virginia Hatter
At this point all of us were having a great dive stuffed with lots of cool sitings. I decided to head for a clump of kelp in front of me, passing just to the left of a huge patch of eel grass, when I heard Lesley’s quacker (which sounds like a duck call underwater) going off right behind me. I turned around to see Lesley frantically waving her hands around telling me to get over and look at something. As I made my way over to the eel grass patch that I just passed, I saw from a distance what I thought was a big halibut or electric eel sitting in the grass. As I got a few feet closer to Lesley I couldn’t believe what she had found, the mythical green sea turtle!

I think all of us were initially stunned by seeing the turtle sitting in our cold green water chomping on eel grass, instead of warm clear water chomping on the green growth found on coral as we were accustomed to. Unlike other green sea turtles that I have seen in warmer waters with their beautiful shiny shells, this one had a thick layer of sand and dirt with a group of barnacles growing on its shell. This certainly worked in its favor as camouflage in the So Cal environment.

We each moved in closer, one at a time, for a good look at the turtle that continued to sit there eating and looking at us. We stayed with the turtle for a good 5 minutes, with divers taking pictures and video before he tired of us and moved on his way. As I looked around with a smile I could tell that this special moment wasn’t lost on this group of experienced divers with high fives and dancing taking place around me.

Seeing special things like this brings a smile to a diver's face and renews the saying, "you never know what you will see”. The pictures you see here are the very pictures taken that day at the Marine Room.

Friday, April 13, 2012

Tips for Basic Regulator Maintenance


Today let’s focus on regulator care. I have seen many regulators come in for service that just make my skin crawl. I just don’t understand how some people do not take care of equipment on which they depend so completely while diving. Regulators with corrosion in the first stage can be avoided with regular care. The gritty sand which gets into your second stage and seems impossible to avoid, especially when diving La Jolla Shores, can also be removed with regular care.

I will give you some tips on how to take care of your life-preserving regulators. I would also like to dispel some of the misunderstandings on the auto closure devices (ACD) on the Aqua Lung regulators and a tip on a relatively unknown fact about the Atomic regulators.

We all know we need to test our equipment before we use it diving. For those of you who have taken a class at The Dive Shack, hopefully you remember when testing a regulator you need to breathe on it. Pushing the purge valve on the regulator to ensure it is working, in fact does nothing to test its proper functioning. When you push the purge valve, yes you make air come out, but that does not test the integrity of the diaphragm. When the reg is in your mouth and you inhale, the diaphragm collapses onto the purge valve which opens the regulator to allow air to flow. Testing your reg by actually breathing on it not only checks the valve, but also the condition of the diaphragm, and the way the regulator will be operating during the dive.
When putting your gear together for a dive, here is a helpful tip to care for your reg. Before you put your regulator onto your tank valve, blow a puff of air out of the tank. This will clean out the tank valve, which will ensure no water or other debris gets into your regulator.

Now let’s talk about post-dive care.

After your dive, when you take the reg off the tank valve, make sure the dust cap is clean and dry before you put it back into place and secure it with the yoke screw. Just remember you do not need to crush the dust cover, finger tight always works here.
Now let’s talk about that ACD (auto closure device) on your Aqualung regulator. Some people think that because of the ACD located on your first stage, the dust cap is no longer needed. This is not true. You should still use the cap, just don’t install it to where you are pushing in on the ACD causing it to open. The reason for using the cap is, even though water is not going to get into the regulator, it will collect in the face of the ACD and if you put the reg onto the tank you are now allowing water to drip into your first stage which leads to corrosion.

When rinsing your regs, slosh your second stage around in fresh water and move any parts that are movable (i.e. adjustment knobs). It’s not a bad idea to use a cleaner like the one sold at TDS, it helps dissolve salts and chlorine. Rinsing will also help get the sand out. Some people like to soak their regs, this is really not needed, and in fact if the dust cover is not on properly water may enter the hose and trickle back into the first stage. After you rinse the reg let it hang to dry. You should make sure to drain any water that collects inside the second stages and in the ambient chamber of the first stage.

Atomic regulators are designed with a small leaf spring in the second stage. The purpose of this spring is to take the pressure off the rubber seat in the inlet valve when there is no air pressure coming down the hose. The up side to this leaf spring is it takes some of the wear away allowing a longer life for your reg. However, the down side to the leaf spring design is, even with the dust cap on, water can get into the hose from the second stage. This is why you should never soak an Atomic Regulator.

For storage, keep your reg in a cool, dry place; never in direct sunlight for an extended amount of time. Some people like to spray their gear with conditioner. It is fine to be one of those people, just make sure you use a food grade silicone (sold at The Dive Shack) and never, ever use an oil. Spray some silicone onto a dry rag and wipe it on the hoses, mouthpiece, and even the reg body if you like. This will keep it looking shiny and new. But remember don’t spray it into the reg; just wipe it on the outside with a clean cloth. You want to avoid getting any silicone on the diaphragm.

The last thing to keep in mind when caring for your regulator is to take your gear in annually to TDS for service to make sure it is clean inside, and that it is working within factory settings. Also, during the service overhaul we freshen your regulator by changing out all its o-rings and seats.

So in closing, to keep me happy and you safe during your dives, make sure you follow the proper assembly and disassembly of the gear. Test your equipment the way it is meant to be used. Clean your equipment thoroughly while ensuring you take care not to allow water into the first stage or the hoses. Store your equipment someplace where it will not get dried out. And finally, make sure your gear is serviced regularly according to the manufacturer’s recommendations.

If you ever have any questions regarding the care and maintenance of your gear, read the user’s manual and or give us a visit at The Dive Shack.

Enjoy your regulator and happy diving.

Friday, April 6, 2012

Humility Expounded

There have been some very significant Rods in my life. Many of you know Rod Tuttle, owner of The Dive Shack. Rod Deutschmann is probably a new character to you though. Rod D. (this could get confusing, huh?) and his wife Robin are amazing photographers and the instructor staff for San Diego In Focus Learning Center (http://www.iflcsandiego.com/). From the beginning my classes with them were mind blowing. They were able to simplify all of the confusing terms and settings for manual photography into simple concepts. They then had you apply these simple concepts to your own camera, in class. Each class was spent outdoors moving all over and shooting. You would concentrate on changing the settings until you achieved the image that you had pictured in your mind. Classes were fun! I learned so much each session, and was excited to come home and apply what I had learned. I was willing to shoot a piece of gravel in the driveway just to perfect these concepts.

Pinhole Camera Image Courtesy of Wikipedia
One of the first things that Rod D. taught me was that all a camera consists of is a box with a hole. In photography, we are just using the camera to capture light. We control the hole or aperture - how large it is and how long it is open - to make our images. That is it! A pinhole camera is the most simple of cameras, and perfectly illustrates the "box with a hole" concept.

Rod D. then simplified things even further for us. He said controlling a camera is as easy as filling a glass with water. The glass in this illustration is your camera sensor. You choose the size of the glass by choosing your ISO. The higher the ISO,1600 for example, the smaller the glass is and the faster it fills. A lower ISO like 100 fills more slowly.

It's your choice

The aperture would correlate with the faucet you are using to fill your glass. You choose how long it is on by choosing your shutter speed which shows up as a number. On my camera that ranges from 60" (60 seconds) to 4000 (1/4000th of a second). You also choose how fast the water is coming out of the faucet by how high you turn it on. On your camera, that correlates with your aperture or f-stop. The lower the f-stop is the bigger your aperture is. A bigger aperture lets light in more quickly so it fills your sensor up faster.

Take some time to find each of these settings on your camera. Get comfortable changing them all. Once you have done this, you have started down the path of taking full control of your images. You are going to love where this path leads you. We will explore each of these settings individually in future posts.






Friday, March 30, 2012

Creature Feature: Cuttlefish




Ngerchong Inside dive site (Palau)
Photo courtesy of Liz Tuttle

Often called the "chameleon of the sea" because of its ability to change the color of its skin at will, the cuttlefish is actually not a fish at all, but really a mollusk. Belonging to the class Cephalopoda (which means head-footed), they are the cousin of the squid, octopus, and nautilus.

The cuttlefish can range in size from 1 inch to 3 feet (and even bigger in the case of the giant Australian cuttlefish which may grow to the size of a small man). It possesses eight sucker-lined arms and two prehensile tentacles (which can be withdrawn into pouches under the eyes) and a sharp, beak-like mouth which allows it to cut open flesh like a pair of scissors, so it can use its tentacles to tear out meat. It hunts during daylight, feeding primarily on small fish, crustaceans and other mollusks.

It moves about in the water by way of a complex propulsion and bouyancy system (much like a submarine). "The cuttlefish propels itself using a series of spurts, drawing water into a compression chamber which it squeezes to jet the water out a funnel under the head. Direction changes can be made by swivelling the nozzle of this funnel, and narrowing the funnel controls speed. Like a submarine, the cuttlefish fills tiny compartments in its cuttlebone with gas to help maintain neutral buoyancy. This helps the cephalopod hover above the ocean floor, because although it has a sophisticated propulsion system its large cuttlebone does not allow it to be overly active, or quick in the water. " [1]


Staying Neutral

Cuttlefish
Redrawn after Clarkson, E.,
Invertebrate Palaeontology and Evolution,
George Allen and Unwin, London,
1979 (Seventh impression 1984), p.167.
The cuttlefish is a bottom-dweller which often lies in ambush for smaller animals. For this way of life, it needs to keep itself at neutral buoyancy, so that it neither sinks nor rises...in order to be able to operate at varying depths and water densities, cuttlefish need to be able to adjust their overall density so as to always remain ‘neutral’ in the water. The cuttlefish does this by an ingenious mechanism. The bony shell actually has many narrow chambers. If these were all filled with gas, they would give a lift of up to 4% of the animal’s weight. However, they are only part-filled with gas—the darker areas shown are where it is part-filled with liquid. The cuttlefish is able to pump liquid in and out of that section as needed to keep the buoyancy ‘just right’. [1]  

The cuttlefish actually has 3 hearts - one for each set of gills and one for the remaining body. Unlike our own blood which gets its red color from the pigment hemoglobin, the cuttlefish's heart pumps blue-green blood which uses hemocyanin pigment to carry oxygen. Its skin is comprised of 3 layers of color pigment cells called chromatophores. These cells are controlled by the nervous system which signals them to expand or contract at a remarkable speed allowing for the hypnotic transformation of the cuttlefish's coloration and pattern.

"A strange fact about the cuttlefish is that it can adopt the female coloration along one side of the body as well as retain the male coloration on the other side. Male cuttlefish are extremely alert when it comes to the females, especially if she is laying the eggs. The male will guard aggressively over the female and this is when another approaching male will use his ability to have a dual look to access the female and trick the male." [2]

Close-up of a cuttlefish eye
Photo courtesy of Wikipedia

Oddly enough, even though it can put on a spectacular color display, the cuttlefish does not see color. Its w-shaped pupil only perceives polarized light which enhances its perception of contrast. Their retina has two areas of concentrated sensor cells called foveae, one to look forward and one to look more backward. There is no blind spot like we have because the optic nerve is positioned behind the retina. The eye changes focus by reshaping the entire eye, instead of reshaping the lens as in mammals.

Cuttlefish are considered to be highly intelligent, like their cousin the octopus. In fact, they have one of the largest brain-to-body size ratios of all invertebrates. Cuttlefish have ink, like squid and octopuses, which they use as a last resort to help evade predators when their camoflague fails. Their predators include dolphins, sharks, fish, seals, seabirds and other cuttlefish. Their life expectancy is about one to two years.


They are mostly shallow-water animals which inhabit tropical to temperate waters, although they have been know to descend to depths of 2,000 feet. Cuttlefish are generally found along the coasts of east and south Asia, western Europe, the Mediterranean, as well as all coasts of Africa and Australia.







[1] Weston, Paula, ‘Fascinating Cuttlefish', answersingenesis.org, March 1, 1997.
[2] Lad, Kashmira, ‘Cuttlefish Facts', buzzle.com