A radio message from the mainland had been received by the ship's captain instructing him to give up the search.
of value ==valuable
There were the belongings of ship officer in the chest.
learn from 从......得知
parts of the log book it was still possible to read.
It was still possible to read parts of the log book.
come to light = become known = emerge 被公开，被发现（不及物动词短语，要用主动语态）
Eg: The secret came to light after his death.
bring sth to light/ review 把……公布于众
Eg: The two brothers reviewed/ brought the secret to light
in a convoy 护航
under a convoy 被护航
confirmed == made sure