Buddy-Link by Affinity Devices, Inc.

Innovative signaling device using ultrasonic digital signals to activate LED's
in your buddy's Buddy-Link, effectively attracting your buddy's attention in
private, not publicly with loud blasts from intrusive noise makers.  Now you
can silently contact your buddy so they don't miss out on the blacktip shark
encounter!  Better yet, you will not spoil your own encounter with the same
blacktip sharks, wondering whether your buddy is near or far — you'll know
when the LED's in your Buddy-Link flash as a result of the automatic signal
acknowledgement your buddy's Buddy-Link sends in response to your
initial transmission!

By tapping the virtual button in the recessed area on the front of a Buddy-Link unit, with the word B-Link displayed over red concentric
circles, your finger blocks an infrared light beam, activating the button and initiating the ultrasonic signal transmissions between
Buddy-Link units.

With Buddy-Link, divers can send two
different private signals and one public
signal.  Dive team members determine
the significance of the different signals in agreement with each other during their pre-dive briefings — of the private signals, one tap can mean
“look up, I want your attention” and two taps mean “come to me.”  The public signal, which is generated with four taps, can signify “emergnecy
recall of all divers back to the boat,” since the signal is sent to all Buddy-Links in the water regardless of their mated channels.

To see what your buddy would see with the Buddy-Link when a signal is transmitted, select one tap, two taps or four taps from the menu above.