What is too much safety !!!

[String]

R Yes you are absolutely right that the radio range is around 5 miles under perfect conditions

Id be absolutely amazed if a VHF radio with an antenna 1" above sea level and possibly covered in water is going to be audible at 5 miles. 1/2 a mile would be more accurate. Have you actually done tests with this in the water with boats known distances away?

since it is a line of sight reception.

Line of sight at 1" altitude isnt much.

I can easily hear the boat radio conversations while sitting at home at 2 miles from the shore line.

Yes. A boat fixed installation VHF is typically 25 watts, a handheld is 5w maximum. A boats VHF goes into a high gain antenna, a handheld has a no-gain rubber duck. A boat VHF antenna is located a few feet above sea level, a handheld is at sea level.

All these factors affect range.

The radio certainly gives much better range than a dive alert, shouting, etc. and

That part i'd agree with. Dive alert and other audible measures are effectively worthless if your boat has its engine running, its windy or anything else.

I think that couple that were diving maybe a year ago (Australia?) that could see their boat for many hours and see planes over their head using a camera flash to signal them would've given anything to have had a radio despite what drawbacks it might have.

A personal 406MHz PLB/EPIRB would be a far more sensible option in their case (and in fact a lot of cases). With those range is never going to be an issue as COPAS/SARSAT will detect the beacon in a few minutes and alert the RCC.

My VHF handheld stays on the boat - i dislike the large bulk and issues carrying, waterproofing and storing as to me the cons outweigh the pros. If i was thinking of an electronic device it would be a 406mhz beacon.

 

[bigken462]

What is a shaker?

I went from this post then skipped to the last page...............To spare me reading through 4 pages of why ppl fall for dive gadgets, WTH is a shaker? One of those El Cheapo flashlight thingies you buy at the dollar store where you shake it up and it shines like a cheap flashlight?

I'm shaking my head at how divers go down looking like scuba Christmas trees. Why not add a few ornaments to all the gadgetry. Lol.

Ya'll have fun,

Ken

 

[Sas]

I went from this post then skipped to the last page...............To spare me reading through 4 pages of why ppl fall for dive gadgets, WTH is a shaker? One of those El Cheapo flashlight thingies you buy at the dollar store where you shake it up and it shines like a cheap flashlight?

I'm shaking my head at how divers go down looking like scuba Christmas trees. Why not add a few ornaments to all the gadgetry. Lol.

Ya'll have fun,

Ken

This is what I learned shortly after making that post:

Deep Blue Dive > ACCESSORIES BCD > MARES SHAKER

 

[bigken462]

Many thanks to ya Sarah, and indeed just as bad as the shaker light. Lol.

Dive safe,

Ken

 

[divekraz]

Las- Click on this link to see my radio Uniden Voyager Handheld VHF Radio

String- I don't know why you seem to be so negative on the radio. I assume you wouldn't tell a diver not to carry a safety sausage or dive alert even though the real effective range in rough seas or less than ideal conditions might only be few hundred feet but then again you just might. The answer to your question of did I conduct any distance tests is NO as the range is wholly dependent on the conditions at the time but I will gladly take 1/2 mile. The comment of 1" is not really valid, in flat seas you can be 1' above the water line and have line of sight for many miles. In swells you can be constantly transmitting and at the top of the swell someone in the area will hear a partial of your distress call and at least be alerted that there is a problem and listen for further transmissions.

Let's take your opinion of 1/2 mile range at best for the radio. What other signaling device do you suggest that will contact the boat with any certainty other than a radio at that distance?
I would expect the most likely scenario for me is coming up from a drift dive or missing the anchor line in poor visibility or the boat coming lose from the moring and with some current I can end up far enough away from the boat that I'm not easy to locate depending on conditions. Now I'm in a situation where I'm dependent on the ability of the captain and crew who have to first determine they have to look for me in the first place, and then look in my direction unless they're so close they can hear the horn. With the radio I'm able to call any vessel in the area and advise of my situation as soon as I surface and hopefully before I'm very far from the boat.

Regarding the EPIRB, since I buy for 2 divers and my wife carries the same safety equipment as I do, the price was a issue and she would be reluctant to use the EPIRB on her own unless it was absolutely a dire emergency. With the radio I extend my radius of contact to the boat and have the ability to at least let someone know what my condition is before calling the coast guard. I'm also not sure how effective a EPIRB is in all parts of the world but I'm pretty sure boats all over the world carry vhf radios.

There are always some negatives to carrying equipment, so it's a trade off to comprimising your trim, buoyancy, weight, cost, etc.. Since my radio is in a pocket and doesn't adversely affect my ability to dive why wouldn't I want the ability to contact and talk to someone at a distance, whatever that may be, if I have a problem.

I will not make any further comments so you can certainly have the last word.

 

[String]

Las- Click on this link to see my radio Uniden Voyager Handheld VHF Radio

String- I don't know why you seem to be so negative on the radio.

Because ive seen them tried

I assume you wouldn't tell a diver not to carry a safety sausage or dive alert even though the real effective range in rough seas or less than ideal conditions might only be few hundred feet but then again you just might.

Delayed SMB everyone should have. divealert id rate is pretty worthless. A torch is very useful as is a strobe.

in flat seas you can be 1' above the water line and have line of sight for many miles.

I beg to differ. Do the maths.

Let's take your opinion of 1/2 mile range at best for the radio. What other signaling device do you suggest that will contact the boat with any certainty other than a radio at that distance?

406MHz EPIRB. Far more reliable.

 

[Blackwood]

You don't need to hold your gauge up to your eyes.
The air pocket acts in the same way as the one in a mask. You can see the same distance either way, it's just difficult to master keeping the air pocket in front of your eyes.

Thanks for the clarification. As was said, though, it seems that having both hands stuck to your face precludes reading of gauges.

 

[ba_hiker]

Response to DaleC and Strand

DaleC, I started carrying the vhf radio when we started diving the wrecks off of Hatteras in N. Carolina. We always went on a 6 pack. With the dives being 50 miles or so off shore and few boats if any in the immediate area, with a very strong current at times, I thought the easiest way to get the boats attention for the smallest
...
issues I don't see any reason valid enough for me not to carry the radio at all times.

I am a licensed ham radio operator, a pilot, a diver, and I kayak. I have 6 or 7 5 watt vhf radios for different bands (marine, ham, aviation -- all from 108 mz to 146 mz) . I have used them from kayaks, and in the water (as a test). I don't bother to carry any radios diving. If you want to great, but you should actually test it in real conditions before you count on it as emergency gear. Really this is true for all the gear that you carry.

Do this test yourself, on a day with conditions that are almost as bad as you will dive in, have a dive boat drop you in the water (after you have jointly done radio tests) and drive away. Keep talking and see what range you get. (Don't do this 50 miles at sea). Or do the beach tests as I have have someone on the shore listen to you as you swim out to sea. Let us all know what you find.

What you can hear is not relevant at all. I can sometimes hear transmitters 60 miles from me. Only thing relevant is who can hear you. Theoretically a 5 watt radio, with a perfectly anisotropic antenna (transmits uniformly in all directions), can be received about 5200 miles away (with current highly sensitive receivers), through a vacuum. Reality is never anywhere near that. Height above ground (electrical ground) is very important.

VHF RF signals are pretty much line of sight. If you can't see them, they probably can't hear you. And even if you can see them it can be impossible to reach them. Sea water is opaque to RF in the VHF bands. 15cm is enough to reduce the effective transmit power to about zero. Waves count. Height above ground matters a lot. I have talked from Santa Barbara to Redding (in california, a distance of about 500 miles) from 10,000 feet. Same radio on the ground does 1 1/2 miles sometimes. At VHF frequencies the ground eats the RF. Thats why hams want to put their antenna way up in the air. The ocean is a great electrical ground. Also radio signals are attenuated near ground, so the rf energy is concentrated in a broad cone pointed upward. This means that even if you can hear the boat and see it, you may not be able to talk to it, its below your radiation cone.

The in the water tests that I have done (from a beach in monterey to me in the water) have shown range as little as 100 feet. From my kayak i have had trouble reaching my buddies 200 yards away, and my antenna is then 3 feet above the water. One time a radio check to a coast guard radio station, from my kayak, showed they could not receive me 1/2 a mile away. Other times i have done better including one test where i got 3 mile range. there are other problems with them too. If any water gets into the connection between that antenna and the unit they will not work at all. And even the water tight (jis7 or jis8) units leak, keep them in a sealed bag even during use.

Many search aircraft have no marine band VHF equipment. The coasties do, but the sheriff, air force, and news choppers don't. The regular aircraft radios won't receive marine frequencies. Even if they do, you will need to be on the frequency that they use. Also remember that just hearing you is not enough. They must find you. Almost no one carries VHF radio direction finding gear except the coast guard boats. Your dive boat almost certainly doesn't. If you can see and communicate with them you will need to guide them in. A compass is really useful for this. You can give them a bering and tell it to them. Be sure to say something like helicopter 180 degree bering FROM ME.

I actually don't want to discourage people from carrying radios. Just don't expect too much, and keep them/use them in conjunction with other rescue gear, including flares and signal mirrors. For daytime (if it is not blowing a gale) a smoke flare (or the smoke part of a day and night flare Day & Night Distress Signal Flare) works great. Thats why military pilots carry (or at least used to carry) them. If you are going to spend $150 (or for me $400, i don't trust Uniden), get the other gear too.

I have a pair of dive pockets that contain emergency gear for off shore dives. They include flares, a small skyrocket flare, dye marker, a streamer, a signal mirror, storm whistle, a strobe light, some fresh water, and a hat with a brim. I always carry a mirror, storm whistle, strobe, buoy, a few light and a dive alert.

 

[tflaris]

My safety gear includes: My common sense, side slung pony, sausage, whistle, two cutting tools (knife and shears) and a B/U flashlight. I also have a compass (is it safety gear or just standard gear?) and for deeper dives I might carry a b/u mask in my drysuit pocket.

I don't know if a long hose counts as safety gear (per se) as much as just a different regulator configuration. I use a 5' primary with bungied B/U myself.

Ditto on this setup. Smart. Streamline. Effective. I might add wet notes in a pocket.

 

[DaleC]

Thanks to all for the discussion re: VHF. I know it can get a little heated but batting around new/different gear is always helpful. Ba, I am interested in your (and others) comments re: eprbs such as the one string recommended. I am wondering about range and if they would be noticed right away and if a response would be automatic.