Shipwreck

Types of shipwrecks
Historic wrecks are attractive to maritime archaeologists because they preserve historical information: for example, studying the wreck of Mary Rose revealed information about seafaring, warfare and life in the 16th century. Military wrecks that were caused by a skirmish at sea are studied to find details about the historic event and reveal much about the battle that occurred. Discoveries of treasure ships, often from the period of European colonisation, which sank in remote places, leaving few living witnesses, such as the Batavia, do occur but only very infrequently.
Some contemporary wrecks, such as the Prestige or Erika, are of interest primarily because of the potential harm to the environment. Other contemporary wrecks are scuttled in order to spur reef growth, such as Adolphus Busch and the Ocean Freeze. Wrecks like Adolphus Busch and many historic wrecks such as SS Thistlegorm are of interest to recreational divers who enjoy diving shipwrecks because they are often interesting to explore, provide large habitats for many types of marine life and have an interesting history.
Very few shipwrecks are famous catastrophes like the wrecks of the Titanic, Britannic, Lusitania or Estonia. There are also thousands of wrecks that were not lost at sea but have been abandoned or sunk. These are typically smaller vessels such as fishing vessels. These vessels can provide an interesting recreational dive but are usually of little interest to historians. They may pose a hazard to navigation and may be removed by port authorities. These vessels are sometimes referred to as abandoned or derelicts.. There are more than 3 million wrecks on the ocean floor, the United Nations estimates.