Many marine mammal populations worldwide are in decline due to stresses from climate change and interactions with anthropogenic activities such as fishing, coastal construction petroleum extraction, and commercial shipping. The advent of the marine renewable energy industry has raised questions, particularly for tidal turbines. However, it is technically very difficult to observe close interactions of marine mammals and underwater turbines, and the likelihood of viewing a rare event such as a collision, is very small. This research seeks to understand the potential risk to a marine mammal from the presence of a tidal turbine by examining the sequence of behavioral events that could lead to a potential collision with the turbine, and the likely consequences to the marine mammal if such a collision were to occur. We examine this potential risk within the context of the physical environment into which a turbine might be deployed, and the attributes of one tidal device, and investigate the biomechanical properties of a marine mammal that may allow the animal to resist injury from a tidal blade collision. The data examined in this research (likelihood of a marine mammal being in close proximity to a tidal turbine, biomechanics of marine mammal tissues, and engineering models) provide insight into the interaction.