The issue is open to any aspect of the subject including the present accuracy of coastal, regional and global tide models; tidal dissipation and its role in geophysics; internal tides and their role in mixing the ocean and in the global ocean circulation; secular changes in tides; and new techniques for measuring tides and analysing the data. The issue also welcomes new findings on earth and atmospheric tides, the role of tides in the origin of life on earth, palaeotides, lake and planetary tides and many other aspects of tides.

The launch of the special issue coincides with the upcoming 100th anniversary of the founding of the Liverpool Tidal Institute (LTI). The LTI was established in 1919 and for many years was the world centre for knowledge of the tides, with Joseph Proudman taking the lead in dynamical theories and Arthur Doodson in the analysis of tidal information from around the world, and tidal prediction. The year 2019 is also the 100th anniversary of the International Union of Geodesy and Geophysics (IUGG), which will meet in Montreal during 9–18 July 2019. The Montreal IUGG will include a Joint Symposium on Tides (with IAPSO as the lead Association) that will be open to all of the aspects of tidal science mentioned above. The symposium will provide a fitting recognition of the anniversaries of both the LTI and IUGG. Contributors to the symposium would be encouraged to write up their work for publication in the special issue.

The special issue is open for contributions now and will stay open until the end of 2019, thereby taking advantage of new findings presented at the IUGG. It is open to any contributor, not only those with links to the LTI or attending the IUGG in Montreal.