Searching for lost things under the sea involves certain skills, techniques and the proper equipment. Divers should not rely only on the information they are given, but use them as clues in relocating the item. Simple rules for conducting an underwater search operation are discussed.
Editor’s note: This is the first of a two part series on search and recovery. This article covers planning, equipment and procedures. The next part will discuss search patterns.
Searching for and recovering things underwater should be simple. If you believe that statement, that’s your first mistake! While the skills needed to conduct a recreational diver-level search are simple, everything else has a potential to confuse the project.
Finding things underwater is full of emotions, ranging from high highs to low lows. On one hand, searching involves using a known set of skills and techniques. On the other hand, intellectual challenges range from bad information, the pressures of needing to find something and the frustration when you don’t.
For this article, assume you are a good samaritan searcher and not involved in police work or scientific diving. You and a buddy are recovering an object that fell off the dock or a small boat. Recovering bodies, criminal evidence or scientific research requires more skills and training than is presented here.
The first rule of searching to be a skeptic. Only believe about half of the information you are given and don’t take for gospel the half you do believe. Remember Sleeper’s Law: The distance an item lost underwater will be found from its supposed location is in direct proportion to the certainty of the loser’s information on where it is sure to be. So, when someone points to a spot on the water and says, “It’s right there,” you can usually bet it is not! The more certain a person is and the louder his voice, the better the odds that the object is not there – and it is probably a ways away!
GOOD INTENTIONS, BAD FACTS
People who lose diamond rings, outboard motors, tackle boxes and other expensive things really want to find them. The problem is that they get flustered at the time of the loss and fail to capture the precise data that would assist in relocating the item. Factor in poor visibility, mud or plant covered rocky lake/ocean bottoms and the relocation can be a challenge.
Before you decide to start a search, ask lots of questions. Listen to the answers and accept them as clues, not facts. Unless you have lots of air and bottom time, the goal is to narrow the search area. Here are some questions to ask. Pick the ones that apply to your situation.
1. Where were you when the item fell in the water? Are you sure it went into the water? (After burning two tanks of air and taking a lot of heat, this author’s search ended when the gold Rolex was found between the boat seat cushions.)
If lost from a boat, was the boat anchored or traveling? If from a dock, where was the item last seen?
2. How do you know that’s the spot? Did you take any bearings on landmarks? What were they?
3. Tell me how it went into the water: Did it slip off the edge of the dock/boat or did the ring go flying when you were casting the fishing line?
4. Was the boat anchored? Have you re-anchored since then? How can you be sure you are on the same spot?
Was the boat swinging on its anchor-line? Is it still swinging over the same area? Or, has the wind, tide, current changed since you lost the item? Did you take a Loran, radar, fathometer or compass reading? How soon after the loss did you record the boat’s location?
5. Did you put a marker buoy in the water? Do you think the buoy had enough weight to go straight to the bottom or could it have floated in a current? What does the marker look like? How long is the line between the buoy and the weight? Is there a chance the marker buoy could be floating and not stationary?
6. Describe the object – size, shape, color.
7. How long ago did you lose the item? Beware: As a neophyte I was once asked to look for a diamond ring lost next to a boat dock. The flat, sandy bottom made me think I’d be an instant hero. After 60 minutes of inch by inch search and no ring, the ringless lady said, “The diver who looked last summer couldn’t find it either, I guess I better give up.”
8. Test the information giver’s estimate of distance, if distance is a key factor. Ask him/her how long the dock/boat/beachfront is. If the person says 25 feet long and you pace it off and it is 40 feet long, you can assume this person’s estimates of distance over water are even less accurate. It is very difficult to estimate distance over water as there are no or few fixed reference points. Most people know the lengths of their own boats, so do not use that as a test question!
All the information you gather by asking question will decrease your time in the water and increase the odds of finding the item.
Armed with topside information, you and your buddy need to assess the underwater conditions. Based upon the underwater conditions and the size of the lost object, you will select a search method. You will also need to address these issues:
- Define the primary and secondary areas to be searched.
- Select a search pattern that best suits the terrain and lost object.
- Decide how to keep track of which geography has been searched.
- Plan the dive within prudent depth/time/air consumption limitations.
Take all the information you have received and factor in your knowledge of the underwater environment. Things to think about include:
- What is the underwater visibility compared to the size of the object?
- Does the object float or could it have sunk slowly and been carried by tides, currents or surge?
- How tight a search need you do? A ring lost on a rocky bottom is a very slow, meticulous search compared to an outboard motor on a sand bottom.
- Are there any dangers for divers such as boat traffic, intake/outflow tubes, active fishing lines or debris on the bottom?
The required equipment depends upon the water conditions and the type of search you will be conducting. At a minimum, wear an exposure suit appropriate for the conditions, normal scuba diving equipment for the area, plus carry a diver’s knife/tool. Start with a full tank of air and monitor your time and depth. If you have a choice of masks, select a style with wide angle vision. Carry marking and signaling equipment such as lines, surface floats, lights and inflatable buoys. These can be clipped to D-rings on your buoyancy compensator, carried in BC or wetsuit pockets or in a small mesh bag. If using a bag, be sure it can be clipped to your body to keep your hands free and that it does not dangle and drag on the bottom.
There is no one correct procedure. It would take an entire book to cover all possible situations, so use the following concepts as guidelines as you plan a search dive.
If you and your buddy doing the search have never performed the underwater technique you plan to use, walk through the procedures on dry land first. Look at your footprints in the sand to judge how accurately you executed the search pattern. Practice the line handling as you would do it underwater. Be careful not to speak directions to each other, since you cannot do that underwater. The person who lost something wants to see you rush into the water and do something quick. Assuming it is a lost object and not a drowning person, you probably have the luxury of a planned, careful response. A few minutes of practice and discussion on execution will result in higher odds of efficiently finding the lost object.
Other preparation includes a review of your U/W communication hand or line signals, discussing the plan of action if the divers become separated, entangled or are non-responsive to line signals. Review how you intend to mark large objects that may require a second dive to retrieve. Establish limits for depth and bottom time. Evaluate the amount of weight on your belt – you need enough to stay down comfortably but not so much that your fins drag the bottom. If searching for a small object that could be covered by silt, use a cave diving type kick. This is where your knees are bent up and you use ankle kicks for slower forward propulsion and minimal bottom disturbance.