During a tropical cyclone, the weather is undesirable and rapidly changing, which poses a serious hazard to coastal and maritime navigation. It was envisaged that the accuracy of the NavIC-based location estimate would be affected if the correction for NavIC signal tropospheric delay was ineffective. In this paper, we discuss the performance of NavIC positioning during the disastrous tropical storm Ockhi, which reached the Surat coast on December 5, 2017, in India. Based on experimental observations during December 5, 2017, Ockhi Tropical Cyclone, we provide the analysis findings targeted at determining the NavIC positioning performance quality and NavIC tropospheric error. We discovered a significant variation in NavIC positioning performance due to the tropospheric delay brought on by the Ockhi Cyclone. We propose corrective actions to preserve the robustness of NavIC positioning performance for various classes of maritime navigation applications and positioning over coastal regions. We pinpointed certain statistical traits of tropospheric contribution to NavIC’s NEU positioning error. This could help study the detrimental impacts of tropospheric influences on NavIC-based positioning and understand how they affect NavIC positioning performance under severe weather deterioration in marine and coastal locations.