BP has been struggling to stop a torrent of oil pouring into the gulf since an underwater explosion sank the Deepwater Horizon drill rig in April, killing 11 rig workers and creating an unprecedented environmental catastrophe.
Costner is confident the oil separator can make a difference, but says for the past 12 years he's been frustrated by the government's and oil companies' lack of interest in his and other technologies.
In testimony before the Congress last week, Costner acknowledged the improbability of his involvement.
"It may seem like an unlikely scenario that I am the one delivering this technology at this moment in time, but from where I'm sitting, it is equally inconceivable that these machines are not already in place," he said.
Pointing out that oil was already "a very big part of American life," he said there has to be a responsible way to deal with the inevitable consequences of such dependence.
He said the oil separator represents an opportunity to be proactive in the face of future spills.
"It represents maybe an opportunity for an industry to go back to work. If we can show that there's a responsible answer to an inevitable problem. This little life preserver, this machine … this could be a pivot point …," he said.
Costner said BP had ordered 32 of the machines. While he acknowledged that a great deal of damage had already been done in the Gulf, he said the machines could still mitigate much of the problem.
"It's not too late … That oil's going to keep coming towards those people. That well has not stopped. So we have to be out at the source, sucking it up … I mean, we have to treat it a little bit like war," he said. "We mustered logistically everything we had to get the beaches of Normandy. We have to muster everything we can to keep it from hitting our beaches."
It's personal to Costner, who can see an oil rig off the shore of his Carpinteria, Calif., home, where schools of dolphins often swim by.
"I'm not a spokesman for anybody … but the ecosystem can't speak for itself," he said Monday. "I'm not a spokesman except for the fishermen who … can't speak for themselves. They're wondering where an answer is.
"And I'm not a white horse. I'm not on a white horse. I'm not the savior to this thing. But I'm kind of saying, I've got a life preserver."
ABC News' Lee Ferran contributed to this report.