The main purpose of this legislation is to prohibit abortions in the admiralty and maritime jurisdiction of the United States. It aims to prevent individuals from seeking abortions on ships or in other maritime areas under U.S. jurisdiction, which could be seen as a way to circumvent state laws regarding abortion. Key provisions of the legislation include a criminal offense for anyone who knowingly performs an abortion in these maritime areas, with penalties of fines and imprisonment for up to five years.