There is no fee to join Extra and you can sign up for free online.
If you choose to sign up by SMS, you will be charged your usual network rate when sending a text message. If you send the text message while you are onboard our ships at sea, we use Telenor Maritime as our onboard network. The Telenor Maritime cost is set by your local phone operator.
You will only be charged for the text you send, not for the text you receive with your membership number included.