[Dive Time][1] – Einer der beiden Favoriten
[Open Waters Dive][2] – Der andere Favorit
[Tivoli Diving][3]
[Blue Ocean Divers][4]
[1]: http://dive-time.net/en/
[2]: http://openwaters-dive.com/index.php/en/contact
[3]: http://tivoli-diving.com/training_d.htm
[4]: http://www.blue-ocean-divers.eu/d_tauchbasis.htm