Tasmania
I think this answers your question, it worked in Tasmania:
MILPITAS, Calif., March 6, 2008 (PRIME NEWSWIRE) -- Sea kayaker Derek Crook was rescued off of the west coast of Tasmania near the Pieman River after pressing the 9-1-1 button on his SPOT Satellite Messenger(tm). Crook, an experienced Canadian paddler, was attempting to circumnavigate Tasmania in a 36 day expedition when he was hit by rough seas near Conical Rocks and flung from his boat on a reef just off shore.
Mr. Crook managed to hold on to his kayak and activate 9-1-1 on his SPOT Satellite Messenger, which allows users to communicate from remote locations around the globe independently of cellular networks, to initiate an emergency response call. The distress message alerted the GEOS International Emergency Response Center used by SPOT, who contacted local Tasmanian rescue authorities with Crook's GPS coordinates.
"I always thought I could self rescue in any condition. However, while attempting to beat the wave breakers and land in a safe zone, my kayak's stern hatch came off and filled with water," said survivor Derek Crook. "This changed everything and I discovered after a long difficult time of trying to save myself, as I was being swept by high winds several miles out to sea, that I was not going to be successful on my own. Luckily for me I had purchased SPOT before my expedition. I recommend SPOT to everyone who strays off of the beaten path."
Mr. Crook was spotted by locals on shore and picked up at sea by their dingy at the same time a search and rescue helicopter arrived on scene and met them on land.
"I was suffering from severe hypothermia and in a very remote area, many miles from any medical attention," added Crook. "Thankfully the rescue helicopter and paramedics, notified by SPOT, were there to transport me to the hospital quickly."
"The authorities were notified by GEOS of his updated GPS coordinates so they knew where to find him. The SPOT Satellite Messenger takes the search out of search and rescue," said Darren Bassel, Director of Marketing for SPOT Inc. "SPOT is waterproof (to 1 meter up to 30 minutes) and floats which makes it very applicable to the maritime community including boaters and off-shore fisherman."
The rescue was assisted by a Westpac Police Rescue Helicopter, a police vessel from Strahan, and search and rescue crews from Qweenstown, Zeehan and Burnie, Australia.