PLBs Can Save Your Life

[Akimbo]

Your mention of heating sealing it in has me wondering if it is not just a metallic material.

I thought of that but it doesn't seem to respond like Aluminum foil.

Just cut it open, it is for science after all. ;-)

Tempting as that is, I would probably call DAN and ask first. The real question is what would you do with that information? Adding a patch to your hood would not have a comparable surface area or got it high enough out of the water to be as effective as their buoy. Besides, my thick head would probably block Radar as effectively as it does most everything else.

 

[rjack321]

It is worth pointing out the importance of coupling the PLB to the buoy.​

Most/many PLBs require unfolding an antenna before activating and keeping it above water to effectively transmit. The obvious answer for divers is to be prepared to physically secure the PLB to the top of the buoy. Unfortunately not all buoys have places to tie into the top. Even if it does, the diver needs to add a means of securing the PLB to the buoy.

PLBs need to have the antenna stay vertical. You don't need to get it elevated off the surface of the water, its "aimed" at geostationary satellites and getting it 2m higher isn't going to change its signal/reception one bit. The best thing you can do is: 1) buy a floating PLB 2) clip off the PLB to a chest Dring 3) lay on your back and set the PLB on your chest with the antenna up.

 

[kelemvor]

Reading some addition 3M technical material, it seems to me that the intention of the SOLAS is for light reflectivity, not radar. So perhaps the link I posted might be trying to compare apples to racecars.

It does bring up using the correct product for the correct task. Maybe using SOLAS on the top of a wing/BC and having a couple squares of tin foil in a bag that you can attach to the top of your 6 ft safety sausage? Give the sausage a tin foil hat as it were.

The SOLAS on the wing would provide ability to be seen from afar using a light source, where a spotlight would be used, and the tin foil "hat" would stay above water and reflect radar?

SOLAS Data sheet - https://multimedia.3m.com/mws/media/474370O/reflective-solas-data-sheet.pdf

The coast guard referes to a LSA IMO Code: https://multimedia.3m.com/mws/media/119949O/us-coast-guard-certificate.pdf Does anyone have an excerpt from that, perhaps that also has something about radar reflectivity and if there are any requirements.

http://www.marinedocs.co.uk/wp-content/uploads/2014/10/LSA-Code.pdf LSA code (2014)

I think you're right. The solas reflectors were designed with visible light (380-750nm) energy reflection in mind rather than marine radar (2.5–3.75 cm) energy reflection. There's a yuge difference. It's just good luck that the 3m does a fine job at both wavelengths.

 

[letterboy]

I thought of that but it doesn't seem to respond like Aluminum foil.



Tempting as that is, I would probably call DAN and ask first. The real question is what would you do with that information? Adding a patch to your hood would not have a comparable surface area or got it high enough out of the water to be as effective as their buoy. Besides, my thick head would probably block Radar as effectively as it does most everything else.

I imagined it didn't respond like a "standard" material, you seem like you understand that bit of information would be important.

I really just wanted to know if you'd cut open your buoy, for science ;-) I probably would have tucked it back in the back of my head where I have the idea swirling around about a buoy/plb/radio that is compact and usable in the back of my head... I can't help but keep thinking of the space between my doubles. But don't like the idea of not having emergency equipment attached to my body at the closest level - not ditchable.

 

[Akimbo]

PLBs need to have the antenna stay vertical. You don't need to get it elevated off the surface of the water, its "aimed" at geostationary satellites and getting it 2m higher isn't going to change its signal/reception one bit.

True but holding it up with one arm up will get old pretty fast -- to say nothing of interfering with my naps. Besides, my arms aren't long enough to keep it out of the water when green water breaks over me. You can't expect dead calm conditions when you are washed out into open sea.

When one thing goes wrong, all the other adverse events like to join the party.

 

[letterboy]

True but holding it up with one arm up will get old pretty fast -- to say nothing of interfering with my naps. Besides, my arms aren't long enough to it out of the water when green water breaks over me. You can't expect dead calm conditions when you are washed out into open sea.

When one thing goes wrong, all the other adverse events like to join the party.

Nothing happens out no where.

Things occur that lead up to all accidents. IT can be as simple as not enough sleep making your reaction times slower on the morning commute and you rear end someone to much more complex butterfly effect/tangential effects.

 

[kelemvor]

Nothing happens out no where.

Things occur that lead up to all accidents. IT can be as simple as not enough sleep making your reaction times slower on the morning commute and you rear end someone to much more complex butterfly effect/tangential effects.

The last time I went to bed late, there was a tsunami in India.

 

[letterboy]

The last time I went to bed late, there was a tsunami in India.

imagine what would have happened if you had been drinking too.

 

[jjardin]

Do you have a Dive Alert inline air horn? If I can see them, they can hear me.

Yep. Last time I used it we were floating in some decent swells off Hawaii Kai for about 40 minutes. About 10 of us were drifting East but the boat was looking out by China wall--we could see them every time we came up on top the swell. Also had the 6'Halcyon Red out, my daughter's 6' Pink Halcyon SMB, and someone else had a similarly sized Orange. If the wind is against you, and the swell is against you, Dive Alert isn't a sure thing. Spouse did have good luck with it in Palau...but that was nice and flat.

That was the second 40 minute wait that month.

(I've also carry smaller 3.3 SMBs cause they shoot easier from depth, at least 1 strobe, signal mirrors, whistles, usually a dive light)

as an aside I've found it easier to hold up the huge SMB by attaching some of the weights to the bottom... it is very tiring maintaining the large buoy vertical. (also make you float higher in the water).

 

[Akimbo]

Nothing happens out no where.

Agreed. Unanticipated and compounding events is our nemesis. I'm live-boating on a drift dive when the boat hits a submerged log and sinks. The outboard may not start as I'm drifting out to sea. My PLB might not work that day. Whitey is overly curious and hungry. Of course I could also be hit by a truck while walking to the store.