You have to keep in mind though that for all of our advancements, the ocean is still a fundamentally hostile environment. One rogue wave takes your ship out and by the time that search and rescue people can be in the area any survivors could potentially be hundreds of miles away. They had a satellite phone with them, so I am inclined to think that they also had a AIS transponder, but these sorts of situations are difficult regardless.

It is standard equipment on an oceangoing boat.

Oceans are huge, and even sattelite transmitters don't cover everything. Example:

http://www.gpstrackersandmore.com/spot2-gps-tracker

http://www.findmespot.eu/en/index.php?cid=102

Even if something like that worked perfectly, oceans are extremely dangerous. A huge wave can destroy even a large sailboat in seconds.