A children's book about the rescue of soldiers from Dunkirk

[laffy2202]

I read a book when I was about 11 (I'm 38 now) about a boy who lived in the countryside on the south coast during WW2, and it described his experience of rationing (he would put buttered bread butter side down on his tongue to increase the sensation), and he also befriended a boy who lived in poor conditions with his family in remote fields. Anyway, they somehow get involved in the little ships rescue of soldiers from Dunkirk. It was a fantastic read and I want to share it with my children now but can't remember the title - does anyone have a clue what I'm about about??!!

[flicrat]

Jill Paton Walsh. " The Dolphin crossing" I think - some time since I read it ! Very sad ending.