The International Symposium on Marine Positioning, INSMAP'86, organized by the Marine Geodesy Committee of the Marine Technology Society, was held 14 to 17 October 1986, under the sponsorship of seventeen organizations, at the U.S. Geological Survey National Center Auditorium in Reston, Virginia. INSMAP'86 was convened to focus attention on the special problems associated with positioning in the marine environment, to provide a timely forum for in‐depth discussions and exchange of ideas, to identify immediate and future applications and requirements, and to promote interdisciplinary and interagency collaboration between numerous investigators and users. The nine sessions and five workshops were attended by over 150 registered attendees representing North, Central, and South America, Europe, Asia, and Australia. In addition, 13 exhibitors set up demonstrations in the corridors leading to the auditorium. Forty‐five papers, including invited addresses, were presented, and are available in a single volume of symposium proceedings.