As global demand for essential materials such as copper and manganese surges alongside the expansion of green energy and blue economy ventures, dwindling terrestrial supplies have made the deep seabed an increasingly attractive target for extracting these highly desirable metals. Advances in offshore exploration technology now make deep sea mining (DSM) a potential reality within the next decade, though its implications for underwater cultural heritage (UCH) remain largely unknown. In this chapter, the potential impacts of DSM on potentially polluting wrecks (PPWs)—World War II-era vessels that, laden with toxic cargoes, are beginning to leak harmful substances into the marine environment—will be explored. While the exact effects of mining activities near PPWs cannot be fully predicted until operations commence, speculative hypotheses can be developed by examining DSM’s broader environmental impacts and reviewing case studies of similar phenomena affecting UCH and marine industries worldwide. Although DSM may not cause immediately noticeable changes to PPWs near mining sites, it could foster a marine environment increasingly hostile to submerged cultural assets. The resulting toxic mixture from mining activities and PPW leaks accelerated by mining may have far-reaching consequences for coastal communities and marine industries around the globe.