 This paper examined the severe bow forces experienced by an oil tanker while navigating through the Arctic Ocean. It used two methods to estimate the bow forces and then applied an exact reliability approach to determine the probability of encountering these forces on a specific route. The results showed that the vessel's route was not consistent with the actual ice conditions encountered, but the reliability approach provided accurate estimates of the probability of encountering severe bow forces. This article was authored by Oleg Gaidi, Ping Yang, Yi Hanshing, and others.