In the investigation of a collision involving recreational watercraft, analytical methods are generally limited when compared to incidents involving land-based vehicles. As is indicated in previous publications, investigators often rely on time/distance relationships, human factors, the matching of damage to determine vessel positioning at impact, and the recollections of witnesses. When applicable, speed estimates are generally based on the boat engine's revolutions. By considering the engine speed, the drive gear ratio, the propeller pitch, and the likely slip of the propeller, an estimation of the boat's travel speed can be made.In more recent publications, it has been recognized that Event Data Recorder (EDR) technology incorporated into various Electronic Control Units (ECUs) used in automotive applications can be beneficial to collision investigation and reconstruction. These devices record data surrounding diagnostic occurrences, airbag deployments, and, with respect to some heavy vehicles, “last stop” and/or “sudden deceleration” events. Formal testing of these devices has shown their accuracy and use in collision analysis.This research examines event data as recorded by specific Mercury Marine ECUs in combination with external data acquisition devices. Specifically, the study focused on validating engine speed data. In addition, recording parameters were researched, as were the effects of a powerloss condition on data files. The results of this research suggest that marine ECUs can be beneficial to accident investigation by recording specific engine parameters and operator inputs immediately prior to a collision incident.