On the water, things go bump in the night … and day, in fog and heavy weather; mostly ships, but also boats of all kinds and the people aboard them. Reaching vessels in distress quickly to render aid or quell an oil spill's spread critically affects the success of search-and-rescue (SAR) and spill-response operations. Timely capturing causal information relating to a casualty's origin through investigation serves to teach regulators and industry alike, and sanctions attendant to reporting obligations incentivize, deter and punish those regulated. To those ends, federal marine casualty reporting regulations apply to defined marine casualties.