<p>Even under relatively benign local weather, hazardous harbor hydrodynamic responses can arise from various forcing mechanisms; among the most common are atmospherically generated long waves (meteotsunamis) and infragravity (IG) waves. The latter are often intensified by long-period transoceanic swell generated by distant intense storms. In this study, we investigate two hazardous events observed in 2024 at Chancay Harbor, Peru, both triggered by extreme transoceanic swell. The 6 November 2024 event was characterized by a sheltered approach that produced strong low-frequency oscillations inside the basin while short-wave agitation remained effectively attenuated. In contrast, the 28 December 2024 event featured an exposed approach and led to anomalous short-wave penetration, with in-harbor short-wave heights approaching ~ 1 m, together with pronounced IG-wave amplification. Using offshore and in-harbor measurements combined with WAVEWATCH III-based swell tracking, we link the far-field swell evolution to nearshore forcing and quantify how approach direction modulates short-wave penetration, low-frequency enhancement, and resonance amplification. Synthesizing the two cases, we identify two contrasting response scenarios for the same harbor under transoceanic swell forcing: (i) a sheltered-approach scenario dominated by resonance-amplified low-frequency oscillations under limited short-wave penetration; and (ii) an exposed-approach scenario characterized by enhanced short-wave penetration and stronger low-frequency amplification, yielding compounded short-wave and low-frequency hazards. The results provide observational evidence for direction-dependent harbor response variability, offering a basis for the future development of direction-aware monitoring and hazard-anticipation strategies at swell-exposed ports.</p>