© 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Exercise Cathach was a large training exercise which utilised and evaluated the use of Unmanned Underwater Vehicles (UUV's) and sensors in a maritime spill Incident involving oil and harmful and noxious substances (HNS). The exercise was a first in terms of the level of robotic systems deployed to assist in survey, surveillance and inspection roles, assessing the scene in real-time before committing first responders for respond and recover operations. The evaluation showed the effectiveness of these technologies to operate in harsh conditions and the efficiency and usability of the real-time data from operations in the field.