Follow the link below to the RYA site:
https://www.rya.org.uk/newsevents/e-newsletters/cruising-news/Pages/marine-radio-distress-relay-protocol.aspx?fbclid=IwAR0HN5b5k2oUb2V5Ed5iCtbuwtCbtYtqA-vKnhBtxhcTrkOYwT41R3oGHCw