Communicating about High Hazard Risk - The kind of risk with no potential for recovery

High Hazard risk is quickly becoming the unilateral risk of concern to all who come across the task of risk management. These risks are typified by have extreme impacts - the kind of impact from which there is no recovery option. Most often these impacts are predicted or analysed to have likelihoods that are at the opposite end of the scale - a likelihood so small that they are considered not possible; that is, until they actually do occur. Even with the very low likelihood, the impact is so great that, if it were possible, they would be rated above the normal top of usual risk scales, e.g. in the defence community ´A´ class is commonly the highest risk [6]. Communicating about such risks to those who manage risk (e.g. a Duty Holder) is key to understanding the complete residual risk profile of an operational situation. How else would it be possible to accept or decline a risk position if it were not clearly communicated and understood? This paper reviews contemporary and historical High Hazard Risks seeking out their particular characteristics; it discusses how risk profiles are understood and communicated about. Contemporary communication theory is introduced, along with identified methods of visualising risk in other industries, so as to show how to convey risks to other persons along the duty holding chain. Two contemporary High Hazard Risk areas from the defence and maritime industry sectors are then re-considered to identify a recommended approach to communication about High Hazard Risk.