In the Gulf of Naples, Italy, a rare prolonged low tide event lasting approximately eleven days, caused by a natural inverted barometer effect, determined extreme environmental conditions providing a singular opportunity to directly observe the long-term adaptive and recovery mechanisms of an Ellisolandia elongata population. This species, inhabiting the low rocky shore intertidal zone, represents a suitable model for studying how coralline algae respond to multiple environmental stressors. To investigate the resilience of the population, we examined structural and functional traits in submerged, exposed, and re-submerged thalli during and following the low tide event. Such approach allowed us to explore the intrinsic physiological plasticity and recovery potential of this species. The prolonged low tide caused bleaching in 74% of the exposed thalli and led to significant decreases in photosynthetic efficiency, PSII-D1 protein levels, and photosynthetic pigment concentration compared to submerged and re-submerged thalli. Despite these detrimental effects, the non-photochemical quenching remained stable, indicating the occurrence of an active photoprotection. Exposed thalli also showed reduced carbohydrate and decreased concentrations of antioxidant compound (polyphenols, flavonoids, tannins and overall antioxidant activity), indicating oxidative stress and mobilization of antioxidant defenses to mitigate cellular damage. Following the re-submersion, photosynthetic activity, pigment concentrations, and antioxidant levels recovered, demonstrating E. elongata capacity to preserve physiological integrity by down-regulating photosystem II efficiency and pigment synthesis during desiccation. Our findings shed light into the adaptive capacity and resilience of E. elongata to extreme climatic events, highlighting the role of antioxidant mechanisms in enabling recovery from multiple stressors. Understanding these physiological responses is pivotal for identifying vulnerability and resilience hotspots within intertidal ecosystems, informing climate-adaptation strategies for coastal conservation planning.