Abstract
Submarines and spacecraft share several features that may promote the presence of fungi, including recirculated ventilation systems, moist areas, and close-quarters living. In this article, we introduce the idea of "submarine mycology" and explore how research on submarine fungi can inform the emerging field of astromycology. We highlight parallels in the fungal species present in both environments, while also noting key differences such as radiation exposure and microgravity. Arguing that submarines offer valuable lessons for spaceflight, we advocate for renewed research using modern genetic tools to characterize submarine fungi.