1 INTRODUCTION

Towage is the service provided, usually, by specialist tugs, generally to assist the propulsion, or to expedite the movement, of another vessel (the tow) that is not in danger and needing salvage. Tugs can range from ocean-going ships to coastal or harbour tugs that are designed with special equipment to push or pull the tow. Modern towage has developed to a sophisticated industry, with power tugs offering a range of services to the offshore industry, and it encompasses much more than just assisting another vessel to prosecute her voyage.1