If you think this will be a regular occurance, take a cavern course from a good instructor. Learning to properly regulate your buoyancy and trim, as well as perfecting kicks that do not stir the bottom will make all the difference. I have been recovering items for many years now and can speak with some authority on this. I have recovered diamond rings, false teeth, guns, tools, bodies, cars, boats etc.
A metal detector sounds good but being able to handle it without making things worse can be trying. Even when you get a hit, finding the item is another thing.
There are great grid search tools and patterns that work great when you can maintain your position in the water and can narrow the search area so that is can be encompassed in the grid. These tool can be built for next to nothing. Car (brake) rotors, floating line (1/4" to 3/8") two floats (milk jugs, bumpers, crab trap floats etc can be used.
Take a brake rotor and add line between the two to the length most likely used in a search. It can be shortened for smaller searches by tying it shorter with a knot that can be untied. To each rotor you need a line that is attached and goes to the surface, to a float. When you deploy this set up the rotors need to be pulled tight so that the line is taut at all times. The heavier the rotors the better. 3/4 ton rotors work well. The lines to the surface must also be tied tight as that you can ascent and descend on them without tangling yourself in them. It is best to tighten this from the bottom especially when on a bottom that gets deeper or more shallow as you move. You may have to adjust these from tme to time. Someone on the surface will always be able to monitor you.
When you deploy them you want to be further out from shore and further from end to end than where they think the object is. You want to know the object is inside of this grid. Mark both ends at the surface in case you have to move to another area so you don't re-search the same area.
You will descend on one end and go to the bottom. Once you get there get neutral and maintain that with a feet higher than you body position. If there is current you can pull against the current and the glide back with the current. If not, a frog kick and pull will serve you best. Your search area will depend on how large the object is and visibility. If it is not jewelry or something small like that vis doesn't matter unless you want it to. It it is very small, move slowly looking as you go. Stay on one side holding the line with one hand. When you get the the end, move the weight (rotor) as far as you can see or feel. Could be a foot or could be five feet depending on the object and vis. Re-tighten the search line and switch hands moving back in the opposite direction. It the object is large you can slide your free hand back and forth as you go. If it is small then you have to look and it is more tedious.
You will double cover each area as you go. If there is a problem you can move to the end and surface in a safe manner. When you find the object you either carry it to the end (if it is small) or tie the search line into it and surface for a rope or lift bag. Tying it in means you can go directly back to it.
If the object is heavy, such as a boat motor, you can lash it to the bottom of the boat, off of the bow, and slowly drive it to the shallows and set it back down in a few feet of water before removing it safely. This is much better on your back.
Like I said, I have recovered many items and this is the best search pattern I have found, especially when there is alot of junk on the bottom. I only have to lift and move the line over and around the object tha is in the way.
Hope this helps. Mark
