The Rottnest Channel Swim is a 19.7km swim from Cottesloe Beach to Rottnest Island, in Western Australia. Every year the event sponsors show their support for swimmers on shore. But we wanted to find a way sponsors and advertisers could show their support for swimmers while they were out in the open ocean.

So we came up with the idea of using underwater speakers to play motivational songs for the swimmers. We took a regular marker buoy and outfitted it with a fully functional, underwater broadcasting system. We called it ‘Go Buoy’. To raise the necessary funds to develop Go Buoy, we sold media space to five advertisers on our underwater broadcast, effectively creating the world’s first underwater radio station. This gave us a budget of approximately $5,000.

The development team included an Art Director, Copywriter, Producer, Production Engineer, Sound Designer and two Creative Directors. We obtained underwater speakers, a marker buoy (which we skinned and branded) and an amplification device that we controlled remotely. We had an event music license from APRA and got permission from the Rottnest Channel Swim Association to place Go Buoy 500m from the finish line of the swim, directly alongside the official swimming channel.

This is an adaption of an existing technology. Underwater speakers are often used by the Navy and marine tourist operators, however there has been no commercial application of the technology to date. That was until the Go Buoy. We took a regular marker buoy and customized it with underwater speaker technology. The Go Buoy provided a new media platform for multiple brands. It gave advertisers and sponsors of the Rottnest Channel swim a way to show support and communicate with swimmers while they were in the water, not out of it. For the swimmers it provided them with motivational music and messages of support to help them over the finish line.

We used an Oceanears DRS 8 Portable Speaker, which has a range of up to 1km in every direction. On the day of the event, we had a boat moored near the Go Buoy providing us with a power source. The underwater speaker was connected to an Audio Isolation Impedance Matching Transformer Assembly, which was connected to a 100-watt stereo amplifier and an MP3 Music Device, which we used to play our music and advertising messages.

The Go Buoy was successfully launched at the Rottnest Channel Swim on the 22nd of February 2014. We reached 100% of our target audience and thousands of swimmers heard motivational music and messages from five different advertisers over an approximate distance of 1.5km (1km as they approached Go Buoy and 500m beyond it to the finish line.) Go Buoy also generated substantial earned media on radio, Twitter, Facebook and in print and sparked lots of great word-of-mouth from the swimmers themselves (see case study).

The Go Buoy could be used at various swimming and water sports events all around the world. It can be easily adapted for use anywhere people are in the water. Beyond providing motivation, a version of this technology could be used to provide information, including public safety information, for any advertising purpose or for entertainment.