Using DSMB as an anchor

[Dan]

Okay
Are you going to be spotted with an SMB?

Post number 3

I was reading this discussion because there was a link to an article that I found interesting about the real chances of being spotted after deploying the SMB
http://www.scubadiving.com/gear/accessories/lost-and-found-sea

Then I found the post, that left me quite puzzled

OK I understand it better now. You are already floating on the surface, but drifting by the surface current. I doubt it’s going to help much.

 

[Firebar]

Every hour you are a drift that search grid expands exponentially. You want to hold your position.

If you have arrested your drift be aware that the people looking for you are using a climatic and tidal model to predict where you are (at least in the US and the U.K.). It’s quite likely that a search would start on your predicted position and then proceed back along your predicted line of advance.

I’d suggest that rather than trying to anchor yourself, where it might be infeasible, if you’re going to be a while you want to use something as a sea anchor to turn your face away from the wind and waves and reduce your risk of water inhalation.

Ideally you’d probably want an EPIRB (only a few hundred quid) or if in coastal waters in the US or Europe an AIS SART/PLB more than you want an anchor (there have been a few high profile rescues of sailors recently with AIS PLBs, their limitation is they are VHF Radio).

 

[IncreaseMyT]

Would need a lot of weight for that I bet, probably more than I dive with. Steel tanks.

 

[WetSEAL]

I may be a beginner, but dropping your weight belt at depth to repurpose it as an anchor tied to a string when there is a strong underwater current just seems like a really dumb idea to me. Too easy for that line to break and cause a runaway ascent. On the other hand tying off a string to an anchor of some type on the bottom like a rock or something to prevent yourself from drifting away sounds reasonable

 

[Diver0001]

no way a weight belt will anchor you to the bottom. You can anchor a line to a wreck or a natural feature but an anchor (especially one as light as a weight belt) would just drag across the bottom if it even remained on the bottom at all..... It would help nothing and create potential risks because the diver would lack the necessary ballast to do stops safely.

no... no... no...

R..

 

[mmerriman]

I may be a beginner, but dropping your weight belt at depth to repurpose it as an anchor tied to a string when there is a strong underwater current just seems like a really dumb idea to me. Too easy for that line to break and cause a runaway ascent. On the other hand tying off a string to an anchor of some type on the bottom like a rock or something to prevent yourself from drifting away sounds reasonable

unless you want that reel back....

 

[Diver0001]

unless you want that reel back....

You'll always get the reel back. You may need to buy new line, which is a few cents per meter at an climbing shop.

R..

 

[Dan]

I may be a beginner, but dropping your weight belt at depth to repurpose it as an anchor tied to a string when there is a strong underwater current just seems like a really dumb idea to me. Too easy for that line to break and cause a runaway ascent. On the other hand tying off a string to an anchor of some type on the bottom like a rock or something to prevent yourself from drifting away sounds reasonable

If you read the link he provided, they are talking about the diver floating on the surface waiting for the boat to come & pick the diver up. I imagine that the diver taking off the weight belt (so he’s becoming more positively buoyant at the surface) and looping the weight belt around the DSMB string, letting the weight belt slide down to the bottom, holding the string & reel as anchor line once the weight belt hits the bottom with DSMB fully inflated.

I can also imagine if the current is pretty strong, the weight belt will be dragging along the bottom. Depending on type of bottom feature, sandy bottom would not hold the diver in place. A rocky bottom would snag the weight belt on crevices, but with a bit of stronger current, that flimsy string would break off.

 

[kelemvor]

As in live boat diving? If so, the normal practice is to send up the SMB, drift with it on ascent while the boat watches, and then surface. If the boat is going to pick you up anyway, why do you need to stay near it?

And how do you pick up the weight belt when you want to get it?

There was a reference to a Jersey upline earlier. I have never used or even seen one, but my understanding of them is that you use cheap, crappy line, tie it off to something permanent, and then cut it loose when you are done. That means there is no need to go back to the bottom to retrieve anything.

Yeah that would be a bad move on a drift dive. Generally you want to actually drift so the boat will have some idea where to expect you to be. If you anchor yourself.... maybe there will be another boat that would pick you up further up current?

 

[Dan]

no way a weight belt will anchor you to the bottom. You can anchor a line to a wreck or a natural feature but an anchor (especially one as light as a weight belt) would just drag across the bottom if it even remained on the bottom at all..... It would help nothing and create potential risks because the diver would lack the necessary ballast to do stops safely.

no... no... no...

R..

You are right. However, I think they are talking about doing this on the surface, after a safety stop done.