In addition to the purchase of the satellite antenna and any optional mounts, you must pay for a line rental (no annual contract required) and add some credits to your account. One credit is used each time you transmit information to the YS6 (boat status request, settings change) and each time YS6 sends you a message, such as GPS location or an alarm. One credit costs approx. £0.10. For satellite communication, you also need to purchase a pair of radio modems to make the connection between the central unit and the satellite antenna wireless.