Deepwater Drilling Royalty Prohibition Act - Prohibits the Secretary of the Interior from issuing any oil or gas lease sale under the Outer Continental Shelf Lands Act with royalty-based incentives in any tract located in water depths of 400 meters or more on the outer Continental Shelf.
Amends the Energy Policy Act of 2005 to repeal royalty relief (suspension of royalties) for deep water oil and gas production in the Western and Central Planning Area of the Gulf of Mexico (including the portion of the Eastern Planning Area encompassing whole lease blocks lying west of 87 degrees, 30 minutes West longitude).
Amends the Outer Continental Shelf Lands Act to prohibit the Secretary from reducing or eliminating any royalty or net profit share for any lease or unit located in water depths of 400 meters or more on the outer Continental Shelf.