The captain of a Greek tanker that spilled 420,000 gallons of heating oil into Narragansett Bay was arrested and charged with violating the Clean Water Act and the federal Refuse Act. Iakovas Georgudis surrendered and was charged in federal court in Providence, R.I., said U.S. Atty. Lincoln Almond. The charges were filed promptly in order to ensure that the captain would remain in the country. Each of the two counts carries up to a year in prison and $100,000 fine or double the actual damages, which the Coast Guard has estimated at $1.6 million. The state was investigating whether a harbor pilot was required to be on board the World Prodigy when it ran aground Friday. Meanwhile, during a hearing into a second spill on the Delaware River, the pilot and captain of an Uruguayan tanker testified that the ship's anchor was dropped too soon, possibly causing it to run aground and leak more than 310,000 gallons of oil.