This chapter provides a general background on the dynamics of the sea surface from the short time and spatial scales of the gravity waves produced by the wind to long scales produced by planetary waves. It considers marine storms (including wind waves and storm surges), astronomical tides, and tsunamis (including events caused by earthquakes, landslides, and meteorological factors). The chapter describes the peculiarity of the regimes in the Mediterranean Sea, their present characteristics, and expected future evolution. © 2023 Elsevier Inc. All rights reserved.