Best signalling equipment from the searchers point of view

[Quetzal]

I like it.

 

[bygolly]

That is a real good point. As far as diving in the US is concerned, it works just fine. The rumor in the satellite market is that Iridium will eventually take over Globalstar. There is a very good chance of this happening in the next year or so. When that happens, the SPOT subscribers will have access to Iridium's 66 satellites in addition to Globalstar's 44. That will easily provide global coverage. But in the meantime, you're right, there are certainly areas with great diving not covered.

I do have a scuba housing in the works specific to the SPOT. A friend of mine is professionally designing it. I'll keep those of you interested posted on the progress of this thing.

My bet is "not to bet" on the merger. The web is very quiet on the subject right now and even the Mobile Satellite Users Association forum stopped talking about the merger rumours in Jan, 2008. The rumours may be coming from the fact that Globalstar is re-selling Iridium phones (with service plans) to unhappy customers. This is something you will not find on their website...you have to specifically ask one of their customer service reps for this.

Regardless, the Spot does work...and very well at that, especially in the orange areas of the coverage map. I would be very interested in the progress of the housing as I would love to take Spot with me on my dives.

Cheers and thanx for your efforts.

 

[beanojones]

Good post

What do you think of rescue streamers. I keep planning on buying one but never get around to it.

RescueStreamer® - Water Safety Emergency Distress Signaling Device

Are they effective?

I love those things for the from the air visibility. But boat captains can't see it. They deploy pretty easily, and the battens keep it from twisting up too much.

 

[FredGarvin]

Tek-Tite waterproof strobes come with a choice of dome cover colors. Clear, blue, amber, red, green and IR.
Is there an optimal color for a strobe that would catch a rescuer's eye from the greatest distance yet would indicate there my be an SOS situation?

I.e. maybe a clear strobe light could be regarded as a marker or buoy rather than someone indicating an emergency, while a red or yellow strobe light would suggest otherwise?

 

[belgianbrew]

I've been thinking about this sort of stuff recently, and it seems when you look at offshore safety items that sailors carry very few are found in the B.C. or in the padi manual. In fact today I went out and bought a strobe to ziptie on to my inflator hose, and I should probably have a mirror too, along with the two whistles I have in and on my B.C.

 

[bjpell]

A rocket launcher would be nice so I can shoot at the boat that leaves me....ha ha LOL!!

LOL!

(At the dive shop)..."yes, I would the blue camo RPG with waterproof firing mechanism on the top-shelf please. Will that attach to my bc with a bolt snap? Id like it to hang next to my PADI dive tables, and whistle for my AOW class? I also herd that you can drop 10lbs off your weight belt too double bonus!"

 

[ba_hiker]

That is a real good point. As far as diving in the US is concerned, it works just fine. The rumor in the satellite market is that Iridium will eventually take over Globalstar. There is a very good chance of this happening in the next year or so. When that happens, the SPOT subscribers will have access to Iridium's 66 satellites in addition to Globalstar's 44. That will easily provide global coverage. But in the meantime, you're right, there are certainly areas with great diving not covered.

I do have a scuba housing in the works specific to the SPOT. A friend of mine is professionally designing it. I'll keep those of you interested posted on the progress of this thing.

Iridium's takeover of Globalstar (if it happens) will not automatically mean that the Iridium satellites will start monitoring spot transmissions. It depends on the kind of transponders on the satellites and their availability. Most up and down links to satellites are not in the VHF band (UHF or higher) if for no other reason than the amount of traffic (static to the satellites). This means those transponders can not be used for monitoring SPOT.

As and aside..
Most satellites use simple transponders that receive a range of radio frequencies, and block convert them into another range which they transmit back to the ground. There is no on-the-satellite signal processing. All phone, radio, and TV satellite signals operate this way. The transponders often receive a block in one band (VHF, UHF, microwave...) and transmits in another band at frequencies that are not 2 or 3 times the received frequencies (to avoid interference between the up and down links). Some transponders may be tuned slightly from the ground, but for most the up and down freqs are set during manufacture, and carefully tested. There are more complicated transponders that do store-and-forward or onboard processing, but they are rare, due to increased weight and power requirements for the transponder.

Additionally satellite coverage does not mean Search and Rescue coverage. SPOT may or may not have agreements in place with local SAR resources. This is not an issue for EPIRBs. There are treaties that mandate response to the EPIRB signals (after following the appropriate protocol for preventing false signals). This is not so for SPOT. If you are in trouble (even in the US) a call from SPOT may not have any pull with the local SAR folks. EPIRBs are different. Someone is responsible for validating and responding to EPIRB signals all over the world, by international maritime treaty (the SOLAS, "Safety Of Life At Sea", treaties). Almost all maritime countries are signers of these and take these duties seriously. A call to officials in say China, by SPOT officials, may not get the same response as a message from a COMPAS satellite to the chinese 'Local User Terminal' or a call to the Chinese 'Rescue Coordination Center' from the US Coast Guard.

Even so actual SAR response is almost always slower than we would wish. The emergency protocols require attempts to validate the signal, get info about the nature of the emergency, conditions at the source of the signal, prioritizing the alarms, scheduling the SAR teams, and dispatching them. It really does not matter how fast the message gets out. All that really matters is how fast the search starts, how much info the SAR teams have about their 'target', and how good that info is. EPIRBs have internationally approved, tested, and PRACTICED protocols. Communications through the system is tested regularly.

In case you missed it, 121.5 is now officially unmonitored in the US. That does not mean that no one is listening (i monitor it sometimes in norcal for amusement) nor does it mean that the coast guard won't have equipment to home in on such a signal. But at some time they won't. In fact the Civil Air Patrol can't home on 406 mz right now!! this will all change, as all get the equipment to monitor the new freq.

 

[LivingWatersVideo]

Navy OnStar thank you!
If I wrapped the bladder of my wing with Mylar would be large enough RADAR signature?

 

[D_B]

Navy OnStar thank you!
If I wrapped the bladder of my wing with Mylar would be large enough RADAR signature?

Here you go ... http://www.scubaboard.com/forums/re...3968-radar-reflective-smb-safety-sausage.html

spun off from this thread

 

[Nemrod]

accidental post