Vessel Drift and Rescue Tug Response Analysis for the Strait of Juan de Fuca to the Southern Strait of Georgia

Protection against a catastrophic oil spill is among the highest environmental priorities for San Juan County. Positioning an emergency response towing vessel (ERTV), or rescue tug, to reduce the spill risk in Haro Strait and Boundary Pass has been identified by the Dept. of Ecology as a priority risk mitigation measure (Oct 2016) and is a recommendation of the Governor's Southern Resident Orca Task Force (Nov 2019). The capability of an ERTV to respond quickly enough to prevent a disabled, drifting vessel from grounding has been questioned. San Juan County partnered with Nuka Research & Planning Group, LLC and UW's Salish Sea Modeling Center to model drift times of vessels transiting the inland transboundary straits. The time for an ERTV positioned in seven harbors was analyzed relative to the vessel drift times in Haro Strait and Boundary Pass. The study concluded that an ERTV responding from Roche Harbor or Sidney could be effective in reducing spill risk, arriving in time to rescue more than 80% of the cases modeled.