The estimated PRoilspill (Singkran, 2013) along with the affected coast and/or important resources at a certain radius outward from the coast into the sea in each coastal province are summarized in Tables 2–4. These estimated local risk magnitudes over space and time are used to guide year-round water activities in the associated areas in this study. That is, at certain months, any oil spill-related activities may be conducted at a certain radius with very low (0.1– 1%) PRoilspill, but they should be carefully handled at a certain radius with low (1.1–15%) to moderate (15.1–35%) PRoilspill, and should be avoided at a certain radius with high (35.1–65%) to very high (> 65%) PRoilspill in each coastal province (Tables 2–4). When oil spill potential is high, the presence of certain human activities/ resources should be strategically discouraged because they may be compromised. This is especially important for infrastructurebased activities that are not easily or quickly relocated, as well as to non-removable resources, e.g., aquaculture, or cultural/historic conservation sites (Santos et al., 2013).