AbstractRecently, Mobile Harbor, Alabama, experienced an increase in vessel size and traffic, which resulted in navigation inefficiencies. This prompted a navigation improvement study that included ship simulations to assess proposed modifications to the federal navigation channels. In 2017, the US Army Engineer Research and Development Center (ERDC) ship/tow simulator (STS) was used to complete a feasibility-level screening simulation (FLSS) study. Areas of focus included: a bend easing, a passing lane, and a turning basin. Over the course of 1 week, a variety of proposed designs were screened and subsequently revised. In 2020, the FLSS study databases were used as a foundation for a more robust study. Approximate meeting locations in the passing simulation track plots were differentiated to capture an instant in time. Additional analysis was performed to identify grounding factors in the passing lane. It was determined that the proposed modifications were feasible under certain restrictions. Through this two-pronged approach, a project deficiency was identified early in the process that allowed for revision and rigorous testing of a preassessed channel.