Stupid Question Alert

[tbone1004]

I didn't necessarily mean in 0 vis conditions, I mean SAR in general. Someone had me looking for a lost pair of glasses yesterday and I couldn't find them. I tried just corn rowing the area but it was hard to stay on track.
I'm just wondering if there are any good books on the subject or anything like that.

Sorry for the hijack eriediver.

some of the ERDI course materials are good, but follow @Lake Hickory Scuba 's youtube channel, Bryan has some good stuff on there and is starting to do a lot more with SAR on there.

Part of the problem with "corn rowing" the area is you really have to use a compass to do it properly as it is one of the more difficult patterns to execute.

This is a decent article on some search patterns. Obviously it requires a fixed reference point for either, and for the pier walk it requires both a pier and a second person. I will usually do arc search patterns if I'm looking for something and will use a reel with it attached to some fixed reference point. If searching from a dock, just tie it to the dock, ideally at the bottom, and if searching from a boat, just tie it to the end of the anchor. Expanding square is one that is much more complicated to actually execute but is quite effective. It again requires a compass though and is not ideal IME for diving in current as your square gets lopsided as you have no real reference to the starting location
Public Safety Diving Search Patterns - Team Lifeguard Systems - Public Safety Water Rescue Training and Equipment

 

[EireDiver606]

@EireDiver606 what depth is your safety stop done at?
Nothing wrong with doing that, though it sounds like you could have benefited from some proper search pattern techniques

We went up and down 3 times to re position ourselves because we couldn’t see anything.

We know how to do search patterns, but I couldn’t see my computer unless it was in my face.

A spool would have complicated things, 3 divers in no vis, underneath a pontoon...

 

[EireDiver606]

I’m comfortable in 1 foot/30cm diving in pitch black and no vis in short circumstances but I don’t think can really be truly “comfortable”.

One of my friends I found out after was digging his hands in the much to find the phone, whereas I thought that we were just going to hover above the bottom with 10cm and look for it.

Turns out that 1 he stirred the mucky shite up and 2 he ended up getting cut from glass or something from digging as he thought he wouldn’t need gloves for a 5 min dive

 

[tbone1004]

We went up and down 3 times to re position ourselves because we couldn’t see anything.

We know how to do search patterns, but I couldn’t see my computer unless it was in my face.

A spool would have complicated things, 3 divers in no vis, underneath a pontoon...

so to be a bit critical.
3 divers is too much for an OW dive team unless you are VERY tight team members and are diving in good conditions. If viz was that bad, you should really be solo diving and in this case for SAR, solo diving is IMO safer and much more effective. @Lake Hickory Scuba is a bit more of an authority on that, but I've done my fair share.
If it was under a pontoon, something stationary should have been dropped, anchor/weight belt, etc. and a circular pattern run from there using a spool/reel. You take some sort of other stationary object that isn't quite so heavy, i.e. a singular piece of lead, a bottle, etc. and use it as your reference marker for when you get back to starting position for that circle.
If you are doing touch and feel, your circles or arc's are really only going out foot by foot since you are more feeling along the bottom than seeing.
If you were doing arc's, you could just have a buddy on the surface holding the reel and as you hit the end of the arc, they give you a foot of slack to start the next one which puts you in "touch" contact with the surface with pull commands

In viz that bad, you shouldn't be searching with a buddy and you shouldn't be "Free searching" i.e. without a line back to a reference point.

 

[EireDiver606]

so to be a bit critical.
3 divers is too much for an OW dive team unless you are VERY tight team members and are diving in good conditions. If viz was that bad, you should really be solo diving and in this case for SAR, solo diving is IMO safer and much more effective. @Lake Hickory Scuba is a bit more of an authority on that, but I've done my fair share.
If it was under a pontoon, something stationary should have been dropped, anchor/weight belt, etc. and a circular pattern run from there using a spool/reel. You take some sort of other stationary object that isn't quite so heavy, i.e. a singular piece of lead, a bottle, etc. and use it as your reference marker for when you get back to starting position for that circle.
If you are doing touch and feel, your circles or arc's are really only going out foot by foot since you are more feeling along the bottom than seeing.
If you were doing arc's, you could just have a buddy on the surface holding the reel and as you hit the end of the arc, they give you a foot of slack to start the next one which puts you in "touch" contact with the surface with pull commands

In viz that bad, you shouldn't be searching with a buddy and you shouldn't be "Free searching" i.e. without a line back to a reference point.

Yeah I’ve done searches before solo and I ACTUALLY found the object.

I agree. But in our club solo diving is a no no and we weren’t properly equipped for solo diving in no vis.

Back to the point, do you think this was unsafe for them to be going up and down 3 times?

 

[tbone1004]

Yeah I’ve done searches before solo and I ACTUALLY found the object.

I agree. But in our club solo diving is a no no and we weren’t properly equipped for solo diving in no vis.

Back to the point, do you think this was unsafe for them to be going up and down 3 times?

I think it wasn't particularly intelligent, but if their ascent rate was slow enough it should have been fine. I would have done it, but would have gone back down properly and wouldn't have needed to surface multiple times to find it....

 

[EireDiver606]

I think it wasn't particularly intelligent, but if their ascent rate was slow enough it should have been fine. I would have done it, but would have gone back down properly and wouldn't have needed to surface multiple times to find it....

We didn’t find it... it was black grunge. Probably sank into it entirely.

 

[boulderjohn]

Speaking solely about the depth of your search following your initial dive (and nothing about the technique), I agree with Tom in post #3. You were essentially doing an extended safety stop, so that part of it was perfectly safe.

 

[boulderjohn]

As for finding things in such conditions, I would be surprised if you were successful. I do not have a good record for finding lost objects myself. I once made a comment like that on another thread, though, and a police diver told me they have a great record of finding crap like guns thrown in lakes. I'll take his word for it.

 

[johndiver999]

I think having 3 people diving together in zero vis trying to all feel for a submerged object is not wise at all. Way better to have one on the bottom and maybe one watching for an smb or something.

Diving 15 feet after a deeper dive is fine, but putting 3 people in the same spot in those conditions because the rules require no solo makes zero sense to me.