The Transportation Safety Board of Canada (TSB) released its investigation report (M16P0378) into the causes and contributing factors that led to the October 2016 grounding and sinking of the US-registered tug Nathan E. Stewart near the entrance to Seaforth Channel. The report underlines the need to effectively and reliably manage the risk of fatigue in the marine industry. The investigation determined that the second mate who, contrary to Canadian regulations, was keeping watch alone on the bridge at the time of the accident, had fallen asleep and missed a planned course change. For more than two days, he had been working a 6-on, 6-off shift schedule, alternating six hours of duty and six hours of rest. This schedule presents a number of challenges which have been well documented by various studies and experts internationally, notably the difficulty in obtaining sufficient restorative rest during the off-duty periods. The Board has made two recommendations following this investigation. Firstly, it is recommending that Transport Canada require that watchkeepers receive mandatory education and awareness training to help identify and prevent the risks of fatigue. Secondly, it is recommending that vessel owners implement comprehensive fatigue-management plans, tailored specifically for their individual operations.