"Tarp" is a common colloquial term for tarpaulin. It is a flexible water-resistant type of cloth, often used as a protective covering for people or objects. Exactly why the ship's crew needed tarps when their vessel hit a reef is difficult to determine from the text provided.
-When the ship hit the reef, the first call was for tarps.
Whats the meaning of tarps?
Tarps, among other uses, can be the material used for ships' sails. Not knowing what kind of ship it was, a possibility could be that the ships engine failed and the only resource for the emergency was the sails.