This review article highlights the three‐century development of our scientific understanding of ocean tides, culminating through myths, paradoxes, and controversies in a global tide model that now permits the prediction of the instantaneous total tide anywhere in the open oceans with an accuracy of better than 10 cm. All major aspects of tidal research, including empirical, mathematical, and empirical‐mathematical methods, are considered. Particular attention is drawn to the most recently developed computerized techniques comprehending hydrodynamical dissipation and secondary tide‐generating forces, finite‐differencing schemes, geometric boundary and bathymetry modeling, and hydrodynamical interpolation of properly selected empirical tide data. Numerous computer experiments are mentioned that were carried out by various researchers in order to evaluate the magnitudes of the featured effects. Further possible improvements are mentioned, especially in nearshore areas, in the Arctic Sea, and near Antarctica, where empirical tide and bathymetry data are either rough or marginal.

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Convection experiments described by Tritton & Zarraga (1967) with electrolytically heated fluid layers were renewed in order to investigate the reported phenomena, which were hitherto unknown and which contradicted a corresponding theory of Roberts. While the apparatus was essentially unchanged, provisions were incorporated to study the possible influence of several flow and equipment parameters on the convection pattern. With the exception of the temperature dependence of the electric conductivity, the new experiments displayed no essential effects of the convection parameters. Experiments with shallow fluid layers revealed a clear co-orientation of the convection flows with the electric current and a strong time dependence of the hexagonal patterns. Experiments with deeper fluid layers exhibited a considerably diminished time and direction dependence of the convection flow, and a significant reduction of the dilation of the cells. Based on these observations, it is concluded that no drastic differences between theory and experiments, and between internal and external heating, exist, provided the heating is sufficiently uniform.

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