Maritime archaeology is a discipline that studies human interaction with the sea, lakes and rivers through the study of vessels, shore side facilities, cargoes and human remains. One speciality is underwater archaeology , which studies the past through any submerged remains. An other specialty within maritime archaeology is nautical archaeology, which studies vessel construction and use.
Maritime archaeology has two important advantages over land archaeology. First the remains of ships and cargoes, even organic materials, are sometimes better preserved under water or in bottom sediments. The second advantage lies in the fact that until recently, shipwrecks were usually beyond the reach of human intervention or salvage, thereby creating perfect time capsules.
Chuck Meide from the Lighthouse Archaeology Maritime Program discusses doing work underwater.