Abstract
The paper reports on the development of a systems model of the sub-sea inspection of an offshore structure in the North Sea. Diving practices, weather conditions, topside management procedures and inspection techniques are incorporated into the model, along with support-vessel capabilities. The model provides a research tool capable of indicating and quantifying ways of increasing the efficiency of inspection diving. Characteristic distributions of many of the variables involved are presented, along with an indication of the consequences of changes in decision and operational parameters. The study indicates that a significant increase in sub-sea inspection efficiency will come from synchronization of topside and sub-sea activities.