four o'clock
`` It was high tide at eight this morning , so it wo n't be entirely out till two . But you know there is about an hour and a half before ebb tide that the flats are bare , and , of course , it 's the same time after that before enough water comes in to float a boat . I do n't believe it 's more than twelve now . Think of staying here till , say , four o'clock . Let 's call again . She might be over on the other side of Clark 's Island . '' `` Wah-whoo-wah !