Two decades after the Exxon Valdez oil spill, cleanup technology has progressed so little that the biggest advancement in the Gulf of Mexico disaster  at least in the public’s mind  is an oil-water separator based on a 17-year-old patent and promoted by the movie star Kevin Costner.

Experts say there have been some improvements in skimmers and other existing technologies since the 1989 Exxon accident in Alaska. Dispersants to break up oil have been far more widely used in the Deepwater Horizon leak in the gulf than in any previous spill, and they have been used for the first time underwater. Controlled burns of oil  only tested in 1989  have been conducted regularly in the gulf.

But more significant advances have been hampered by a lack of money for research and laws and regulations that make it difficult to test new ideas and introduce improved equipment. In the gulf spill, the laying of boom and the skimming of oil remain a last, and not completely effective, line of defense for coastal areas. Skimming, for instance, cannot be done in rough seas and is often limited to daylight hours because of the difficulties in detecting oil at night.

Even officials with BP, the company responsible for the gulf spill and cleanup, acknowledge that most of the equipment in use represents improvements in old technology, and cite the lack of major spills in the past two decades as one reason.