Elkhorn coral

Definately not Acropora Palmata, A.palmata is an endangered carribean reef species, to be honest im not even sure if this is a coral, it could be a sponge as their are several that grow like this and no hard corals that sprint to mind, can you tell me did the lobes weft around with the current, there is a mediteranean coral guide http://oceana.org/sites/default/files/reports/Corals_Mediterranean_eng.pdf ill check through the species when i have a bit of time and see if i can ID it