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.

1 comment:

  1. Did you by chance find an anchor there??

    One of my favorite classes.

    ReplyDelete