Mt Suribachi is very active, the whole island has been rising since WW2. That and the currents are what made the navy give up trying to build harbor there.
I was there in 2007ish and I don't recall that many ships being visible compared to what is in the link.
I remember reading somewhere that it's all on a giant lava dome and sometime in the future will probably collapse and sink back into the sea. The Earth is a strange place.
