Cape Verde Islands, Canary Islands, Azores
The area between Capo Verde and the Canary Islands is covered by Thuraya. Thuraya provides, as regards the retrieval of weather data, the highest data rate with max. 60 kbps download. The Teide on Tenerife excludes the area west of this mountain of Thuraya and Inmarsat coverage. To hike in this region you must use an Iridium phone.
Thuraya network covers up to the Azores. This is for sailors still useful, however the line of sight to Thuraya satellite will be interrupted when reaching the coast. On the Azores islands themselves you should prefer Iridium to Thuraya phones.