YB Tracking offers an alternative for boats who aren't equipped with a satellite phone.
Essentially it uses a Bluetooth connection to turn an Apple or Android smartphone or tablet into a 2 way satellite text messenger, allowing it to send and receive SMS and email from anywhere in the world.
The quick start guide can be found at: QuickStartGuide.pdf
Pricing information can be found at: YB Products (scroll down the page until you get to Running Costs).
100 credits should be reserved to meet NoR 13.2.