Drifted for 8 hours - Pensacola Pass, Florida

[Scuba-74]

What equipment malfunction. His BCD filling with air is not a malfunction, it's a feature.

Am I missing something or is it bad reporting?

Unless they were making negative entry?

Five Tips for Making a Negative Entry

 

[BikerBecca]

Unless they were making negative entry?

OK, still not an equipment malfunction. That would be a diver malfunction.

 

[Scuba-74]

OK, still not an equipment malfunction. That would be a diver malfunction.

Which is what they are trying to say. Let the air out, then accidentally added it back in (not sure how it can be done by touching hose with elbow, but oh well), then failed to check it was completely out before jumping in.

EDIT: I actually never had to make a negative entry, and don't know what the protocol is for what to do if you get stuck on the surface for one reason or another (or if your buddy gets stuck on the surface) - insufficient weight, air in BC, didn't jump fast enough because the boat was rocking, etc. But I'd imagine that if I'm ever in this situation we would discuss it before hand, and it wouldn't include searching on the bottom for 10 min.

 

[2airishuman]

Not sure quite what to make of this.
- If the intent was not to to a drift dive, but rather have the boat remain anchored, I would have taken a compass heading on the location of the dive boat and descended to take advantage of the reduced current near the bottom.
- For a drift dive, everyone should have an SMB.
- Either way, his buddy should have surfaced and alerted the boat so a search could start immediately.

Taking a VHF radio on a dive poses a number of problems. While there are submersible ones (I have three), they can't be taken to depth unless they are in a housing or something. They're big, and that's not a convenient thing to do.

The range of a VHF radio depends on antenna height, anyway, and without some means of getting the antenna well above the water, the range is going to be limited. This affects both the voice and AIS (location data) functions. While the USCG facilities are very good, they are not designed to pick out a low-power radio that is only about a foot above the surface. VHF radios are essentially line of sight so unless you are within sight of a boat they will not work.

 

[Dan]

I actually never had to make a negative entry, and don't know what the protocol is for what to do if you get stuck on the surface for one reason or another (or if your buddy gets stuck on the surface) - insufficient weight, air in BC, didn't jump fast enough because the boat was rocking, etc. But I'd imagine that if I'm ever in this situation we would discuss it before hand, and it wouldn't include searching on the bottom for 10 min.

The way I was thought to do a negative entry, once you are in the water, you duck and descend head first, fins up, and pull your butt dump valve to bleed any residual air (this is a muscle memory thing as you would never be sure about how much residual air left in your BCD).

A good buddy would also look up to see if you are not too far off him and keeping up with him, especially when the surface current is swift.

 

[Dan]

The new nautilus has no radio function, it just triggers the DSC alert in other radios. To be honest I don't know what that "call" would look like on my Standard Horizon DSC radio. Everyone has DSC in the USA (its been a requirement for a long time) but nobody actually makes digital calls - every VHF call I have sent or received for the past 12 yrs has been analog, including calls to the USCG vessel traffic, and a rescue helicopter that was looking for a PLB in my area.

Net, how that alert is triggered without actually making a radio call is a bit of a mystery to me. I do have one experience where the USCG called my home phone number because an old boat of mine triggered the DSC alert. I had not deleted the MMSI from the radio because Standard Horizon limits how many MMSIs you can program (2) without a factory reset. I guess someone pushed the button but then failed to answer hails back. I suspect the response without being able to answer via VHF radio is more like a weak PLB than anything else. They get the DSC alert, they call the contact numbers to try and figure out if its real or a false alarm. Lastly a vessel is deployed to the coordinates.

When I hit the red button on my new Nautilus Marine Rescue GPS (MRG), the “call” would look like the one in the video below (skip the 1st 14 minutes). It’ll provide an audible Man Overboard (MOB) emergency alert or generic emergency alert if your VHF Marine Radio receiver does not have special alert sound for MOB. Then the receiver display will show my MMSI 972-69-6005 and GPS coordinate. The 972 is the code for MOB, MMSI MID formats | e-Navigation Netherlands. So no need 2-way radio voice option in this case.

 

[Dan]

The Nautilus is an AIS - it broadcasts a signal to other AIS equipped ships with location,...

The new ones are. The old ones just have DSC.

The new ones have both DSC & AIS that will be sent out alternatively. They come with their unique MMSI specific for displaying Man Overboard (the first 3 digits of the MMSI, 972, MMSI MID formats | e-Navigation Netherlands).

 

[chillyinCanada]

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A ScubaBoard Staff Message...

Let's keep this thread on the incident please. Discussion of the PLBs etc. already has an ongoing thread. Thank you

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[GetDownScuba]

Monday morning quarterbacking here, but they should be using a tag line in seas such as he described. Glad he survived.

 

[markmud]

I use a pre rigged crack bottle dsmb

Hi DD,

You are imparting some good advice, along with others--THX!

What is a "pre-rigged crack bottle DSMB"?


markm