Spotting them can simply depend on the time of day and tide conditions.

BBC: Springwatch 2010: Seals on Blakeney Point in Norfolk

However, by this time the tide was turning and many leading educators were questioning the effectiveness of mixed ability teaching.

BBC: Setting, streaming - how schools teach

I'm unable to work or parent effectively for months or even years at a time - then the tide goes out and I feel "normal" for a while, able to function again.

BBC: Bipolar holiday