In the 25 years which have passed since the Report on Small Craft Harbours was first published in 1969, marina development has gone through a dramatic transformation. In 1988, the Task Committee on Marinas 2000 was formed for the purpose of updating this report. Since much has been learned about the technical aspects of planning and designing small boat harbours over the past 25 years, this updated report, Planning and Design Guidelines for Small Craft Harbours (ASCE Manual 50) provides the practicing civil engineer with state-of-the-art guidelines for the planning, design, construction, and financing of small craft harbours. It is organized in four parts. The first section discusses planning and related environmental considerations, and suggests an analytical planning process. The next part covers the protection of small craft mooring facilities and access areas. The third section is concerned with the improved design of inner harbour structures. The last section explores the economics and finance of small board harbours. This revised manual provides a valuable reference to the professional civil engineer by presenting the factors involved in harbour development and by providing basic background information needed as design input.