[Tunis Afrique Presse] Tunis -- The coastal city of Mahdia will vibrate on June 25-30 to the rythm of the Trapanis Underwater Photography Festival and the CMAS Underwater Photography Championship organised under the aegis of the World Underwater Federation (CMAS) and CMAS Africa, in parternship with the Tunisian Federation of Subaquatic Activities and Life saving (FASST).