Harbors and navigable waterways are places of high risk for hazardous materials transportation disasters. For one thing, these are locations of large amounts of flammable, toxic, explosive materials. Risk is all the greater because differences in organization, procedures, techniques, equipment, and vocabulary between landside and waterside environments create a perceptual and 96organizational void at the water’s edge. Without a determined effort to bridge these differences, integrated contingency planning necessary for effective response to sudden-onset disasters typical of hazardous materials emergencies is extremely difficult.