I'm looking for time series of wave height/ period, velocity currents and wind speed/direction specifically for the Qiangzhou strait in China.
Global data sets could also work.
You can retrieve that information from ERA5 reanalisys data. It cover the whole world from 1979 until almost the present. The resolution is 0.25°x0.25° and includes many fields that characterize ocean waves. here is a list of available fields for download in the "Ocean Waves" section:
And there is of course, winds data as well.