Sunday, April 21, 2013

Searching Davy Jone's Locker

I was asked last week what specialty I like to teach the most. I gave it some thought.  I like a lot of them, Underwater Navigation, Equipment Specialist, Wreck Diving etc.  But the one that I come back to the most is “Search and Recovery”.  I have thoroughly enjoyed teaching this specialty.  The two pillars of search and recovery are 1) something is lost or 2) something needs to be recovered. The something is lost can be a variety of things. For example, a set of keys has been dropped overboard, wedding rings left a hand during a water volley ball game, an outboard jumped ship or a prop was there then it wasn’t.  The search starts with getting as much information as you can before you start the search. I talk to as many people that were there and saw what happened as I can.  Nobody ever remembers everything about where the boat was when the keys went into the water or when the outboard jumped off the boat but by interviewing a number of people you can get a better idea of the area that you will search.  Another tidbit of information to consider is the ability of the item to drift to the side after it enters the water.  Keys on a ring tend to whirlybird to the side as much as 6 -10 ft. from where you saw them go in.  Gold rings or heavy outboards tend to go almost straight down but a prop only comes off in reverse and will spin sideways and back as much as 25 – 30 ft. In that case you really need to know the position of the boat when the prop left it.
I found this prop using a sweep search, feeling my way along the bottom in zero visibility
Used a 50 lbs lift bag
After the information gathering is completed you the have to determine how you are going to search and what equipment you will need. Sometimes you will need the assistance of one or more other divers and it becomes a group adventure. The location and area of search will often dictate the search pattern.  In the case of the outboard, if the visibility is good you can do your search up off the bottom using an expanding box search with your compass. Low or zero visibility will require a search on a line feeling your way along the bottom. I do this type of search a lot.  In the case of the rings you may have to use an underwater metal detector. This is what I used to find the wedding rings in the picture.  It’s fun to investigate and set up the search.
I used an underwater metal detector on this find.
Recovery starts after your search finds what you’re looking for. In the Search and Recovery course we learned the use on knots and had some fun with lift bags. When you find something small like the wedding ring or keys recovery is a no brainer. But when you find a large prop or an outboard motor you don’t just pick them up and tale them to the surface.  In the course we learn how to secure a lift bag to various items and safely take them to the surface never being below the item in the event that it drops off the lift bag. . When working alone I secure a second line that ties the recovered item back to the dock, boat or shore.  This ensures an easy find again if the item drops off the lift bag.  
After 14 years in the muck, I found it.
Last week I did a job that was just recovery. The barge at the marina flipped over and was stuck upside down in the mud. No big search here, just look for the 8ft x 20ft bottom of the barge sticking 1.5 ft. out of the water out in the marina.  This one would fall under advanced recovery and would not be something that a diver would do without special training. The recovery involved overheard environment, entanglements, hanging equipment, zero visibility and ass kicking current. (yes, a ripping  current in a marina).  After surveying the situation underwater it was my job to take a strap, an anchor shackle and 2000lb lift bag under the barge and fasten them on to the bottom of the crane in the mud.  Just work the strap around the beam of the crane in the mud, then remove the bolt from the shackle, work the shackle though the strap, attach the lift to the shackle and put the bolt back in with zero visibility , 40 degree water , 5mm gloves and a ripping current.  Then do it again. When my job was done the boat guys took over and towed it to be lifted out of the water. I love Search and Recovery.
This one was easy to find.

Sunday, April 14, 2013

A Lion of a Problem

As everyone in the dive world is aware, there is a problem with lionfish in the Caribbean.  This voracious eater was accidentally released into the waters of the Atlantic and has been wreaking havoc ever since.  The lionfish was able to gain a fin hold in this new environment quite easily.   With poisonous spines protruding from its sides to discourage predators from making a snack of them, and a hypnotic dance that mesmerizes its prey while the hunter closes in for the kill, they are pretty much able to decimate reefs without a worry.  Dive operators and concerned conservationists have been brainstorming to develop some plan to restore balance to the reef ecosystem but it always seems that human interference, while possibly solving one problem, usually creates a new one.
On our recent trip to Cayman Brac, I found it fascinating how friendly the grouper were, swimming right up to divers, allowing them to be petted.  Waiting for us each time we descended, the piscine pets followed us along the wall like dogs on a walk.  In areas where the coral heads were separated by sandy areas, the grouper set up “neighborhoods,” and if a grouper from one coral head continued with the dive group to the next coral head, he would be confronted by neighboring fish and chased away, back to his own territory.  It didn’t take long to figure out why they behaved this way.  Our divemasters, trained and encouraged to hunt lionfish, brought a spear on every dive.  Divers would point out a lionfish and the invader would be good as toast. (Or should I say sushi?)   As the divemaster lined up his shot, the fish would gather like spectators in the coliseum.  Once the fish was dispatched, it was taken off the spear and left for the grouper, triggerfish, or whatever fish were around to take advantage of a free meal.    

It was fun at first to interact with the fish in such a way, their usual timid behavior transformed into a new openness.  However, it is one thing if the grouper are begging for a free meal, but what about other animals?  On one of the sites we visited, there was an enormous green moray.  I mean a monster!  In fact I spotted him on the reef 60ft below while on my safety stop and thought at first he was a shark!  The divemaster told us that he is really careful to look out for him when he spears lionfish because this guy will take the fish right off the spear without a shred of trepidation.  He also volunteered that on Little Cayman, they no longer spear in the marine park during  diving tours because the sharks were catching on that they could perhaps get a tasty lionfish snack if they joined the dive group!  Divers tend to get a little nervous when sharks are acting too friendly, and imagine what would happen if a tourist, camera trained on the lionfish-divemaster interaction came between a shark and his snack?  
Another thing to ponder would be what happens when a grouper starts following a diver that is spearing something other than lionfish?  Instead of getting a meal, he may become the meal.
On other Caribbean islands, they hold spearing competitions and lionfish barbeques, teach lionfish hunting courses, and encourage the serving of lionfish at local restaurants, but none of these plans  is entirely successful, and there is likely no perfect solution.  In any case, man introduced the lionfish where it did not belong, and man is attempting to correct this problem.  Let’s just hope that a new problem is not created in the process.

That is it for this week.  As always, share the blog, like you on Facebook and leave a comment to let us know what you think of the blog and suggestions for the future.  Until next week, Cheers!

Sunday, April 7, 2013

Six Things to Know About Night Diving

Night diving is one of those activities that at first blush, seems silly.  After all, one of the first assessments that divers make of a new dive location is the “vis.”  Why, then would a diver want to purposely dive where (or when) the visibility is zero?  Anyone who’s done a number of night dives knows, however, that night diving can be exciting and give a whole new look to a familiar dive site.  In addition, just as the plants and animals in, for example, a forest, can vary depending on the time of day and the amount of light, so can the organisms in the aquatic world.  For that reason, night diving remains a popular twist on diving, so I would like to share my top six tips for night diving.

Number 1
Always familiarize yourself with the site during the day.  It will be easier to navigate your way in a dive site if, in addition to your compass and marker lights, you have a mental image of the site.  Look for signs of creatures that you will want to find at night, such as basket stars, which are tightly bundled during the day, but open up at night to feed.

Number 2
Take particular care to plan your dive.  How will you enter?  How long will you be down?  What is your objective?  What will be the plan if separated?   Underwater, in the dark, there is a little less margin for error and complicates communication.  Therefore, making a clear dive plan that both buddies agree on will go a long way to relieve stress and

Number 3
Have a well maintained dive light and a backup dive light.  Having a backup light will not only help to decrease the stress that can sometimes accompany night diving, but it will be a real life saver if your primary light fails. Be sure the light is secured to you before entering the water.   It is good to have a light with a wide beam for night diving, but for your backup, the smaller light that you use during the day will work fine.  Be sure to have fresh batteries in your light and turn it on before you enter the water.  

Number 4

Observe good light etiquette.  Maintain control of your light, and do not shine it into other divers’ eyes, effectively blinding them.  When making hand signals at night, point the light toward your body and make the hand signal in the beam so your buddy can see it.  When pointing something out, do not shine your light directly on the animal.  Rather, shine your light so the item is illuminated by the edge of your beam, where the light is less intense.   Alternatively, trace a circle around the animal with your light.  Be respectful of the marine life, too, remembering that divers can give predators an unfair advantage by pointing out unsuspecting prey.  In addition, parrotfish, for example, can only make one cocoon per night, so if you disturb them while they are resting, they will be vulnerable to predators the rest of the night.

Number 5
Learn how to get your buddy’s attention at night.  As you are already aware, sound travels much faster in water than in air, so it is difficult to determine where the sound is coming from. Banging on your tank or use an underwater signaling device to attract your buddy’s attention during the day usually is a good method because the buddy hears the noise and then looks in all directions until he finds you.  At night this does not work so well.  A better technique would be to stay close to your buddy and use your dive light to signal him.  Shine the beam of your light at his beam, and then move your beam slowly from side to side.  Then move your beam slowly to the thing that you want to show your buddy, or to your hands if you need to communicate something (low on air, ascend, etc.) to him.

Number 6
If you need to signal the boat at the surface, use a variation on the “big OK.”  Inflate your BC so you are comfortably at the surface.  With your arms raised over your head, point your dive light so it shines on your head.   If you are in distress, shine the away from you and wave your arm.  If you are diving from shore, set up your dive beacons to guide you back in to your entry spot.  

If you want to learn more about night diving, and do a few dives under the supervision of your dive instructor, consider taking the Night Diving Specialty course.  This course delves into more planning and navigation techniques, and provides many opportunities to get practical experience.

Who wants a FREE Manta Diver’s T-shirt?  We are looking for guest bloggers to share their dive stories.  How did you feel on your first open water dive?  What is your favorite Great Lakes wreck dive?  What is your favorite marine animal and why?  Your blog must be your own work, and preferably accompanied by a few photos.  If we post your entry, you will receive a FREE Manta Divers T-shirt.