I’ve discovered Previmer.
This French and English site has tide streams for Jersey, Guernsey and the English Channel.
It is possible to see hour by hour tidal stream data around the coast in more detail than the Admiralty tidal stream atlas.
What I find impressive is the level of detail and accuracy of the tide stream atlas on Previmer. This is very handy when planning sea kayaking trips a few days in advance.
The data is presented in metres per second so you need to convert into knots via a converter site such as Onlineconversion.com A metre per second is roughly 1.95 Knots.
The site is currently in beta and at the moment it is free to use.
Previmer has been created in partnership with the French Naval Hydrographic and Oceanographic Service , Meteo France, Ifremer and other French marine research organisations.
Wave height data, wave buoys, tidal streams, tidal surges, sea temperature,salinity Phytoplankton production and other data can be accessed via Previmer.
Plenty to keep you busy following the changes in the ocean and planning trips.
My thanks to Colin at Sea kayaking Brittany for alerting me to this site.