Vessel strikes – collisions between ships and whales – occur throughout the world’s oceans (Figure 10.1) (Laist et al., 2001; Van Waerebeek et al., 2007). First reported in the late nineteenth century as ships reached speeds greater than 13–15 knots, lethal vessel strikes remained relatively infrequent until the mid-twentieth century (Laist et al., 2001). Since then, as the number, speed and size of vessels increased, reported vessel strikes have similarly grown (Figure 10.2) (Laist et al., 2001; Vanderlaan et al., 2009). Vessel strikes involving large whales have emerged as a global conservation concern, largely due to evidence that vessel traffic is increasing (Tournadre, 2014), vessel strikes are increasing (Laist et al., 2001; Vanderlaan et al., 2009), vessel strikes are hampering the recovery of certain endangered whale species (e.g., North Atlantic right whales; Knowlton & Kraus, 2001) and, where enacted, the success of mitigation efforts to reduce the threat of ship strikes may be mixed (e.g., Lagueux et al., 2011; Silber & Bettridge, 2012; Silber et al., 2012a, 2012b; Vanderlaan et al., 2008; van der Hoop et al., 2013).