Vessels at times incur mechanical failures or casualties that can lead to loss of life, property and environmental harm if not responded to promptly. The concept of offshore routing for the Pacific was first explored in a 1978 study conducted by DOT and later in 1999 by the Pacific States-British Columbia Oil Spill Task Force. These led to the establishment of recommended offshore routes for vessels incorporated as “standards of care” incorporated in the U.S. Coast Pilot. Monitoring of vessels operating offshore with AIS (Automatic Identification System) has revealed the routing measures are largely not being complied with. The PacMMS will substantially elevate adherence through active monitoring and communications. By transiting well offshore vessels and responders have more time to respond to a marine casualty before a vessel and crew are in extremis. Additionally, early detection of a casualty via active vessel monitoring (vessel not under command or not making way) aids the early dispatch of response resources or delivery of needed parts or technicians.