87 replies to this topic

[peterbj7]

I presume by "strobe" we mean a signalling one, not a camera "flash" one? I can't remember the make of mine, but it's bog standard and I've had it below 400ft with no problem whatever.

[Landlocked Dive Nut]

I have a multi-purpose light.....purchased originally as a light for my camera setup, it's also easy to remove from the tray arm and use as my night-dive light (it's nice & bright). Cool thing is, it also has a flash / strobe function. Probably designed to attach to a dock or shore area so you can find your exit at night, I'm sure it would work really well as an emergency strobe at night if I'm adrift. Now, I'll just have to remember to take it on every dive.......

[secretsea18]

I presume by "strobe" we mean a signalling one, not a camera "flash" one? I can't remember the make of mine, but it's bog standard and I've had it below 400ft with no problem whatever.

A strobe is a strobe is a strobe. An intense pulse of light. Can be used to illuminate a nudibranch or signal your position to a boat or a plane. Camera strobes are extremely powerful compared to many other little "strobe" that are just a blinking light.

[Wakemaker]

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A strobe is a strobe is a strobe...

Um, what if your life depended on it? Flash intensity may not be nearly as important (or desired) to a helicopter pilot with night vision... as...

... "approved" survival strobes which will continuously flash so-many-times per minute, typically for 8 hours before the flashes begin to dim, and continue operating / floating even if the victim looses muscle control and/or consciousness.

It's also easier to play "Not it" with your dive buddy using a smallish life jacket style strobe than, a really big camera one.

(Maybe it's about time dive camera strobes should have a Distress Mode setting. It is the right color to signal distress, after all)

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[secretsea18]

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A strobe is a strobe is a strobe...

Um, what if your life depended on it? Flash intensity may not be nearly as important (or desired) to a helicopter pilot with night vision... as...

... "approved" survival strobes which will continuously flash so-many-times per minute, typically for 8 hours before the flashes begin to dim, and continue operating / floating even if the victim looses muscle control and/or consciousness.

It's also easier to play "Not it" with your dive buddy using a smallish life jacket style strobe than, a really big camera one.

(Maybe it's about time dive camera strobes should have a Distress Mode setting. It is the right color to signal distress, after all)

Most "strobes" that are used/sold in dive shops are not "survival" strobes like might be used in military or maritime survival suits. They are basically a flashlight with a repeater on them. If you know the heli is there, the pilot will not miss my camera strobe flash. And unless using an approved lifejacket, which a BC is not, your face will probably be in the water if you become unconscious, cause otherwise there is muscle tone present.

[peterbj7]

A strobe is a strobe is a strobe

Except that a signalling strobe is designed to be visible from a wide range of angles and does not have a focussed beam, whereas a camera one clearly is focussed. And a camera one has precisely controlled timing, whereas a signalling strobe merely pulses at regular intervals.

[Wakemaker]

... "Although these EPIRBs also include a low power 121.5 MHz homing signal, homing on the more powerful 406 MHz frequency has proven to be a significant aid to search and rescue aircraft. These are the only EPIRB types which can be sold in the United States." ~ U.S. Coast Guard Navigation Center (Strong print added by the post-it; me)

"With a DF-430, we get lock-ons [to a 406] at 150 miles sometimes," Yarbrough says. "An aircraft that is locked on knows where you are. The pilot has a needle to steer by. That's a big step forward in rescuing you in a timely manner."

"The 121.5, by contrast, works only as a homing signal at short range -- often less than five miles, according to a Coast Guard Office of search and Rescue report delivered at the 2008 beacon manufacturers' workshop in San Diego."

"Starting with $2.6 million from its Integrated Deepwater System Program for modernizing aircraft and vessels, the Coast Guard began equipping its C-130Hs and Falcons with 406 MHZ homing equipment in December 2006. Now it is installing the gear on its helicopters. Evnetually all of its aircraft will have DF-430s."

~ Soundings, Real Boats, Real Boaters, (magazine - soundingonline), August 2009, "New technology improves EPIRB searches," pg. 39 and 41.

This bit is obviously, all relative to mariners in distress, not divers. That perspective might change when there are a lot more response ships with rescue aircraft aboard. C-130s and Falcons cannot pick-up anything out of the water. They can, however, be the aircraft launched from shore to locate a device that was activated 500 miles off the coast of Panama or around the Great Barrier Reef's 100,000 square miles of ocean. I will check the quoted part of the article for dyping erros later.

Edited by Wakemaker, 11 September 2009 - 11:35 AM.

[Wakemaker]

Total number of U.S. SARSAT rescues for the calendar year 2009: 174Does anyone know when the 2009 counter stopped? I have been advised that there have been 40 SARSAT rescues for year 2010. Cospas-Sarsat System rescues counter. "A SARSAT (Search and Rescue Satellite-Aided Tracking ) rescue is counted when a beacon alert was the primary means of notification or primary locating method for a rescue.""11 Nov 2009: A 406 MHz EPIRB was activated approximately 230 miles south of Louisiana in the middle of the Gulf of Mexico. Coast Guard District 7 (CGD07) received a Mayday distress call from a power fishing vessel. CGD07 requested the owner of the fishing vessel to set off the EPIRB as a precaution while the Coast Guard was on route to them. The Coast Guard safely airlifted the fisherman from his vessel on 11/11/09 with no injuries. The fishing vessel later sank and the EPIRB was still active until the battery died. NOT A SARSAT RESCUE"12 Nov 2009: A 406 MHz EPIRB was activated 8 NM east of Ocean City, MD. The EPIRB registered to the 44 foot fishing vessel Sea Tractor was detected. Three persons were reported to have been on board. The LANTAREA Rescue Coordination Center launched Coast Guard Cutters and small boats, H-65 and H-60 helicopters and a C-130 aircraft. After 18 hours of searching, all they could find was a debris field where the emergency beacon was located. There were no survivors. NOT A SARSAT RESCUE http://www.capemayco...t-of-new-jersey

[Capn Jack]

That perspective might change when there are a lot more response ships with rescue aircraft aboard. C-130s and Falcons cannot pick-up anything out of the water.

Those multi-motor bus drivers do carry really cool life rafts they can drop that will change your survival time from perhaps minutes to days.

Edited by Capn Jack, 25 November 2009 - 01:19 PM.

[Wakemaker]

Total number of U.S. SARSAT rescues for the calendar year 2010: 42

[Wakemaker]

One I-4 satellite is 60 times more powerful than an Inmarsat-3. The I-4 series is expected to continue in commercial operation until about 2020 ...
www.inmarsat.com/About/Our_satellites/default.aspx

If you have any information about how I-4 satellites are utilized in SAR or emergency calls, please post it. Navstar and NASA employees may be our best bet.

[Wakemaker]

Total number of U.S. SARSAT rescues for the calendar year 2010: 42

UPDATE:
I hope this message finds everyone well. It has been a very busy boating season in the USA. Stay safe over, on, in, and under the water.

Total number of rescues for the calendar year 2010: 188

As of 2010Aug23. (I think the offical link to the data is at http://uscgsar-onscene.blogspot.com/)

[WreckWench]

Hey Ron...its great to see you again and for keeping this very important thread active!