This review volume, the third in the series, presents the latest topics for discussion, which provides invaluable information to coastal and ocean engineers around the world. In the first paper of this volume, entitled “Internal Solitary Waves”, Grimshaw reviews the basic theory of weakly nonlinear waves in an incompressible density-stratified fluid. The internal solitary waves solutions and effects such as friction, refraction and finite amplitude on internal solitary waves are also discussed. In the second paper entitled “The 3/2-Power Law for Ocean Wind Waves and Its Applications”, Toba gives a thorough review on the field evidence and physical background of the 3/2-power law and the associated wind-wave energy spectra. Several wind-wave prediction models are also discussed. Goda, in his paper entitled “Directional Wave Spectrum and Its Engineering Applications”, gives a brief historical overview of the development of directional wave spectrum. He presents several standard formulas for directional spreading function for engineering applications and discusses the effects of directional spreading on nearshore currents and wave forces on coastal structures. In a companion paper entitled “Analysis of the Directional Wave Spectrum from Field Data”, Hashimoto describes the maximum entropy principle method, Bayesian directional spectrum estimation method and the extended maximum entropy method for estimating directional wave spectrum. Hashimoto also introduces a new developed Doppler-type directional wave meter for field measurements. Finally, in “Reliability-Based Design of Coastal Structures”, Barcharth introduces a design procedure that makes it possible to optimize a design and/or to design to a specific failure probability level.