Personally, I would (and did) go with the SPOT tracker.
SPOT SPOT II GPS Satellite Messenger at West Marine
It's cheap to buy (about $100) and has been proven to be effective. If you pay for the yearly service you can send a message to Mum so she knows you are OK. She can also track your progress if you (and she) like.
No, it's not an EPIRB, but for coastal use *I* think it's an effective, cheaper, alternative.