Epidemics and the Ocean, the 4th volume in the “Science of Ocean and Human Relations” series, was published on March 4, 2021, just as the third wave of the COVID-19 pandemic struck. For the safety of marine products and the conservation of a healthy marine environment in the future, the rise of ocean pathologies is linked with increasing economic activity. When considering the post-Corona era, there should be much that we can learn from the history of mankind’s battles with epidemics as played out on the ocean.