ten o'clock sharp
She felt a delicious , shivery thrill pass over her that was one part fear and the other part rapture . `` Phil , '' she whispered a few seconds later , when she heard her chum stirring in the berth above her , `` can you feel fins growing where your feet are ? Your flop in the bed sounded as though you were a real mermaid ! Just think , at ten o'clock sharp we are going down to explore a new world ! I wonder if there were ever any girl divers before ? You are awfully good to let me go down first . '' `` No , I am not , '' answered Phil soberly .