From missing a captain

One day , me and my helper were on a ship called Dei Gratia. I was the captain of that ship. We were on the Atlantic ocean because we were investigating sharks.
    Suddenly we saw a ship that was in the middle of nowhere. We got to the ship to ask for same water because we had drank it all. When we got on the ship we heard someone who shouted , so we went downstairs and we saw a man that was tied  on a chair. He told us that he was the second man in charge and he was hoisting the sails of the ship with the captain , when a group of pirates got on and threatened them. One of them hat him on the  head and he had lost conscience.
    When he woke up everyone were gone. He screamed for hours but nobody answered back.
    We untied the boy and searched for people , some pirate or captain , but mo one appeared. The boy  and us we were afraid that the pirates had killed the captain or thrown him to the sea but a mysterouse clue appeared. The captain‘s backpack was gone , so we figured out that the captain had escaped , but where?. We kept searching for more clues but we didn‘t  find anything else.
    We about give up when the boy had an idea  and went running where the lifeboat  was and surprisingly it was gone too. The captain had really escaped and  we relived. The boy ran to the captain 1s cabin and there we found a map with a red circle made on a nearby island.
    Finally we found the captain in a dark cabe on the island and we rescued him. Luckily , things , went well at the end.