In reply to Rob892:
Berry Head has options at high tide, but does depend specifically what you want to do. You can down climb into the the Great Cave at any state of tide. You can also traverse round to the start of Moonraker unless the sea is rough and/or tide is very high, but traverse through back of Cave is about 5c (and if you fall off you'll end up in the sea, potentially with all the gear/rope).
You can ab to the Moonraker ledge at high tide with a long rope (probably 80m but check pitch length, tie a knot in end of rope, and have an escape plan, etc etc).
Alternatively go deep water soloing, as that's all much better on a high tide!
Chair Ladder not sure, as only been there at low tide. Probably can ab or downclimb to some higher ledges, but a fair bit of the crag base will be under water. Again helpful to know where to ab from (or be with someone who does), as you cant really look down on the crag from the top.
Sennen and Bosi are obvious none tidal alternatives.
Post edited at 08:59