The worst witch all at sea

[ROBINDESBOIS]

That' s the title of a book. My question is should' t it be the worst witch of all at sea?

[poli]

All at sea can mean confused or adrift (a la deriva).
So, I would guess the title refers to the worst witch in a dilemma.

[Perikles]

Originally Posted by poli

All at sea can mean confused or adrift (a la deriva).
So, I would guess the title refers to the worst witch in a dilemma.

It looks like you are correct. Googling gives

The Worst Witch es una novela infantil escrita e ilustrada por Jill Murphy. La protagonista es Mildred Hubble, una joven bruja que es la peor alumna de la academia para Brujas de Ms. Cackle.