This document is divided into five parts. The first part deals with flotation analysis features and definitions to acquaint the engineer with elements common to the various methods and the meanings of the terms used. The second part identifies and describes the various methods used. To accomplish the minimum intent of this document, techniques could be limited to those needed for flotation analysis only; however, because of the close relation between flotation analysis and runway design, methods for the latter are also included. In fact, runway design criteria are used for flotation and evaluation in some cases, and are periodically the governing procedure in specific, if isolated, instances. From time to time, it may be necessary to deal with runways built to obsolete criteria. Therefore, a listing of most of these constitutes the third part.