Fatal events taking place in World War (WW) I and II have left behind important historical evidence as an underwater cultural heritage (UCH) (e.g., shipwrecks, submerged aircraft, war artifacts), lying in peace at the bottom of, among others, the Mediterranean Sea. The article aims at exploring the challenges for UCH protection/preservation and sustainable exploitation with emphasis on this sea. UCH is so far dealt with in a “silo” approach by marine archaeologists or heritage professionals, who often ignore its potential for serving local sustainable development goals. The paper elaborates on the value, but also the complexity, multi- and inter-disciplinary as well as multi-actors’ nature of UCH management and sustainable exploitation, perceiving these as a “wicked” planning problem. It attempts to illuminate various important dimensions of this problem, such as its glocal (global/local) context; the conflicting and, in certain cases, inconsistent UCH legal protection framework, touching upon a variety of spatial scales; the contemporary policy frameworks favoring UCH management; etc. Exploration of these dimensions reveals open issues or gaps that need to be filled, and sets the ground for a more holistic and integrated UCH research and management approach for building up the yet largely untold, Mediterranean WW I and II UCH narrative; and shifting this area from a sea graveyard to a place of memory and cultural enrichment.