OK - here's a tough problem but I'll ask it anyway.
I occasionally need to be "on call" with my job. That means I have to be contactable via cell phone.
So -- how can I be contacted if I'm swimming laps?
I can park my cell phone on the pool deck with a towel covering it and then check it but that means I can't do an extended # of laps.
=> Is there any apparatus that would allow me to wear an earbud to let me know the phone on the pool deck is ringing so I can then immediately swim back to answer? Kinda like a "Bluetooth" ear receiver?
Any thoughts?
Thank you.
I poked into this question a bit, and what I found is not encouraging. The problem is that electromagnetic radiation does not propagate well through water, so unless you are very careful with frequencies, antennae, etc., water is, for all practical purposes, opaque.
This link points to a surprisingly recent (2011) study on electromagnetic wave propagation in fresh water. Figure 4a, in particular, shows total attenuation as a function of frequency for a transmitter located in air, to a receiver located in shallow, fresh water, like what we'd have in a pool. The optimal frequency range for this kind of communication is 3-100 MHz. Bluetooth operates at 2.4 GHz; though this study didn't include frequencies that high, it's pretty obvious that attenuation at 2.4 GHz would be over 100 dB even at a depth of 1 meter.
Undeterred, apparently a company called Brando tried to sell a Bluetooth headset called Wavetooth a couple of years ago, advertising it as the "1st waterproof bluetooth headset can swim". According to one reviewer, "Bluetooth range limited to about 8 inches underwater", and according to another, "range is good, but the receiver has to be above water". Given the physics, those results aren't surprising. You can't order a Wavetooth from Brando right now; the website says it's out of stock.
It may be possible to engineer a system like the one you're asking about, and maybe someone has done it, but I couldn't find it. I do not think Bluetooth frequencies would work; I'd look for something that operated in the range 3-100 MHz.
I poked into this question a bit, and what I found is not encouraging. The problem is that electromagnetic radiation does not propagate well through water, so unless you are very careful with frequencies, antennae, etc., water is, for all practical purposes, opaque.
This link points to a surprisingly recent (2011) study on electromagnetic wave propagation in fresh water. Figure 4a, in particular, shows total attenuation as a function of frequency for a transmitter located in air, to a receiver located in shallow, fresh water, like what we'd have in a pool. The optimal frequency range for this kind of communication is 3-100 MHz. Bluetooth operates at 2.4 GHz; though this study didn't include frequencies that high, it's pretty obvious that attenuation at 2.4 GHz would be over 100 dB even at a depth of 1 meter.
Undeterred, apparently a company called Brando tried to sell a Bluetooth headset called Wavetooth a couple of years ago, advertising it as the "1st waterproof bluetooth headset can swim". According to one reviewer, "Bluetooth range limited to about 8 inches underwater", and according to another, "range is good, but the receiver has to be above water". Given the physics, those results aren't surprising. You can't order a Wavetooth from Brando right now; the website says it's out of stock.
It may be possible to engineer a system like the one you're asking about, and maybe someone has done it, but I couldn't find it. I do not think Bluetooth frequencies would work; I'd look for something that operated in the range 3-100 MHz.
