Search and Recovery search patterns

[GulfDiver77]

I am taking AOW and I am studying for the search and rescue elective dive. I was wondering which pattern most divers here use ie: expanding square,U-pattern,or rope patterns? Or non of these and some other pattern.

 

[james croft]

Depends on the location you are searching. Rope searches tend to be the most consistent. Near shore arc searches are good. Some circle searches are good on a flat bottom. When I can do it depending on the bottom and type of structure on the bottom I prefer the jackstay search pattern. A lot of times it depends on the object I am searching for.

I have had the various types of search and recovery courses offered by various recreational diving agencies and found them to be less than ideal and the patterns they recommend often not usable in real world diving. They look good in the book but are not very good. I recommend using a variation of the jackstay search. Some classes teach you to have a diver at each end of the rope which is anchored at each end. The divers search as they swim towards each other. When they get to the opposite side they move the anchors a few feet further and repeat the process. This is not safe as it does not allow for the divers to communicate with each other or aid each other when they get entangled. The best method is for the two divers to travel together, grasping each others hand with fingers interlocked with each other, while allowing the rope to slide through the divers hand. They can communicate with each other by hand squeezes or stop their buddy by clamping down on their hand attached to the rope. When the divers get to the end of the rope, they move the anchor and then swim back towards the opposite end of the rope as they search. Once they get to that anchor, they move it a few feet and repeat the process. This allows the area to be searched by both divers more than once. This method is greatly superior to those methods taught in other courses and you can actually find what you are looking for with this method. The first method the search patterns are parallel to each other. The last is a zig-zagging pattern that is redundant.

The goal is to find the object and say " Here it is " or to be able to say with certainty " It ain't there ". With a jackstay search that is properly done you won't have to say " I couldn't find it."

 

[ReefGuy]

What James Croft said. Depends on the conditions and what you're looking for. The jackstay is probably the most effective search, but depends on the bottom being mostly flat and featureless. I don't have any confidence using any search that doesn't use a rope (ie, expanding square), but then again, I do most of my searching when the vis is effectively (or really) 0. We've found items as small as a .45 automatic using an arc search, and a keyring using a jackstay, both in 0 vis.

 

[The Kraken]

. . . and, the expanding square is good in concept, but exceedingly difficult to execute properly, especially in a low visibility environment. One must have a designated navigator setting course and counting kick cycles or whatever means of distance calculation is being employed.

the K

 

[GulfDiver77]

I appreciate the comments. I was wondering how well the different search patterns work in the real world. I am constantly dealing with engeneering that looks good on paper but isn't worth a **** in the real world. I am glad I joined this board. I have recieved alot of useful information and advice. I have finished all of my book work for my Nitrox and AOW just waiting for the dives now.