Diver to shore communications?

[Waterwulf]

We're heading up to the Colorado River below Parker Dam for a few days with the motorhome and I am planning on doing some snorkeling and diving if the water conditions are good. I'll be snorkeling/diving solo. My Wife will fishing downstream from me while I'm having my water fun. I was going over my gear and was checking my diver down tow along buoy when I had an idea. Underwater communications.

Slates and sign language work fine for close up but I'm wanting to be able to talk to my Wife while I'm diving and she's fishing. Yes, you can talk into a regulator and "talk" to your partner but you gave to put your regulator right up against the other persons ear for it to work. Yeah, you can understand it if you practice. Radio communications don't work very well underwater because the water blocks the signals. Low frequencies and high power transmissions work kind of sorta ok but most times, it's a wired circuit with a cable between the diver and the boat/shore. That wired circuit thing got me to thinking about a way to use radio communications to talk to the surface while I'm on a dive.

Diver Down flags have been required for a long time and nowadays, having a tow behind buoy is pretty much the law for snorkelers and shallow dives. Fine! So there's times I have to drag the friggin' thing around with me but why not make it do something besides help to keep me from getting run over by Jet Skis? My buoy has a flag on top of it and is actually large enough to hang onto while in the water. It would have no trouble at all holding up a thin antenna cable with an antenna attached. The cable would be attached to the tow line and would follow it down to me. That would completely negate the problems of underwater transmissions because the antenna is in the air.

I have a FCC License to operate GMRS radios up to fifty watts. I have hand held radios that will transmit up to eight watts and that's plenty. It would not be difficult to mount one inside a water proof acrylic housing with a push button for "Transmit". A button mic would be mounted inside my regulator and a waterproof earpiece inside a neoprene hood to keep it tight against my ear. (Maybe both sides) The mic could be mounted inside my snorkel too. The surface person would just use a regular hand held radio.

Thoughts?

 

[Angelo Farina]

Underwater communications is usually done wearing a full face mask and an ultrasound transceiver.
Something like this:

Buddy Phone Through-Water Transceivers (1/2 Watt Output Power) - Ocean Technology Systems

The Buddy Phone® D2 is a digital, micro-miniature, ultrasonic transceiver allowing communication between two or more scuba divers and / or surface stations. (Sold Separately, Does Not Include FFM)

www.oceantechnologysystems.com

 

[tursiops]

Underwater communications is usually done wearing a full face mask and an ultrasound transceiver.
Something like this:

Buddy Phone Through-Water Transceivers (1/2 Watt Output Power) - Ocean Technology Systems

The Buddy Phone® D2 is a digital, micro-miniature, ultrasonic transceiver allowing communication between two or more scuba divers and / or surface stations. (Sold Separately, Does Not Include FFM)

www.oceantechnologysystems.com

The OP is in a special situation: he'll always have a line to a surface float, and his environment is very shallow (i.e., acoustic multi-path is likely) and very noisy.

 

[Gone for diving]

We're heading up to the Colorado River below Parker Dam for a few days with the motorhome and I am planning on doing some snorkeling and diving if the water conditions are good. I'll be snorkeling/diving solo. My Wife will fishing downstream from me while I'm having my water fun. I was going over my gear and was checking my diver down tow along buoy when I had an idea. Underwater communications.

Slates and sign language work fine for close up but I'm wanting to be able to talk to my Wife while I'm diving and she's fishing. Yes, you can talk into a regulator and "talk" to your partner but you gave to put your regulator right up against the other persons ear for it to work. Yeah, you can understand it if you practice. Radio communications don't work very well underwater because the water blocks the signals. Low frequencies and high power transmissions work kind of sorta ok but most times, it's a wired circuit with a cable between the diver and the boat/shore. That wired circuit thing got me to thinking about a way to use radio communications to talk to the surface while I'm on a dive.

Diver Down flags have been required for a long time and nowadays, having a tow behind buoy is pretty much the law for snorkelers and shallow dives. Fine! So there's times I have to drag the friggin' thing around with me but why not make it do something besides help to keep me from getting run over by Jet Skis? My buoy has a flag on top of it and is actually large enough to hang onto while in the water. It would have no trouble at all holding up a thin antenna cable with an antenna attached. The cable would be attached to the tow line and would follow it down to me. That would completely negate the problems of underwater transmissions because the antenna is in the air.

I have a FCC License to operate GMRS radios up to fifty watts. I have hand held radios that will transmit up to eight watts and that's plenty. It would not be difficult to mount one inside a water proof acrylic housing with a push button for "Transmit". A button mic would be mounted inside my regulator and a waterproof earpiece inside a neoprene hood to keep it tight against my ear. (Maybe both sides) The mic could be mounted inside my snorkel too. The surface person would just use a regular hand held radio.

Or just leave the radio up top,
with plug in mic, run it underwater. In a plastic bag,
(well made make something better after initial testing)

Those external microphones are cheap enough

 

[tursiops]

Or just leave the radio up top,
with plug in mic, run it underwater. In a plastic bag,
(well made make something better after initial testing)

Those external microphones are cheap enough

Isn't that what he is describing?

 

[Gone for diving]

My buoy has a flag on top of it and is actually large enough to hang onto while in the water. It would have no trouble at all holding up a thin antenna cable with an antenna attached. The cable would be attached to the tow line and would follow it down to me. That would completely negate the problems of underwater transmissions because the antenna is in the air.

I have a FCC License to operate GMRS radios up to fifty watts. I have hand held radios that will transmit up to eight watts and that's plenty. It would not be difficult to mount one inside a water proof acrylic housing

Maybe but I thought he was taking a radio with, and having 1 wire to the surface for the antenna..

 

[tursiops]

Maybe but I thought he was taking a radio with, and having 1 wire to the surface for the antenna..

Yeah, maybe, not clear from his post. Keeping the radio at the surface make a lot of sense. The long wire is probably better to carry the mic signal than to be to an antenna anyway, less loss.

 

[Waterwulf]

Yes, I know how it's usually done and I'm sure that's the best way....probably. But, I'm a hobbyist and a tinkerer. I'm interested in building something that will work for what I have in mind. I usually dive/snorkel solo. No, it would not work for those times when I wasn't towing a buoy but would all other times.

I never thought about leaving the radio on the surface and just taking the mic/headphones down. I think (but am not sure yet) that in my case, it wouldn't work as well as taking the radio down and running an antenna wire up to the buoy.

The reason for that is because the only time it would be used, is for shore based dives/snorkels. That's the only time that I would tow a buoy. That's pretty short range and I can pump out up to eight watts on a hand held. That would overcome any antenna line loss but I'm not sure if I could compensate for a long mic/headphones line.

Since I can do all of my own machining, electronics and Acrylic vacuum forming and probably have most of the parts already, I figure I could build one unit for under a hundred dollars. No, it won't have a helmet but it is possible to speak inside a regulator. If I'm just snorkeling, I'll probably use a separate mic. I also have some throat mics laying around so one of those might be interesting to experiment with.

It's still just an idea at this point. I was curious if anybody had ever tried this before.

 

[Gone for diving]

I figured coaxial cable under water won't be that great...
but maybe you can get away with 2 wires side by side, because there is no interference under water.

 

[OTF]

This is all feasible. The problem you'll run into is how difficult it is to speak clearly with a reg in your mouth. This likely requires a full face mask, or a reg with a custom cup-style mouthpiece. Or it may be possible to train in some alternate enunciation techniques like ventriloquists use and speak clearly through a reg, maybe.