An Arabic speaker translated the note and said it's from a girl in Morocco named Iman who is writing a prayer!

The prayer is to the messiah of the Shia Muslim sect of Islam.

She asks for his protection and guidance, she also asks to be cured from her sickness. She wishes to pass her upcoming exams. She also wishes that all boys and girls can find their destined partner, including herself. Toward the end of the letter, she asks for the health and prosperity of her parents; and also mentions that her siblings are going on a trip and wishes that all goes well.

It is not uncommon for people praying to the messiah, Imam Mehdi, to write the prayers and send them away -- like in a bottle into the ocean!