The lawyers for two BP rig supervisors charged with manslaughter in the Deepwater Horizon disaster says the indictment should be dismissed because the standards the men are accused of violating didn't even exist at the time the explosion happened.

Donald Vidrine of Lafayette and Robert Kaluza have each been charged with 11 counts of involuntary manslaughter and "seaman's manslaughter."

Lawyers for both men say federal rules that were in place at the time of the blast on April 20, 2010 did not mention or mandate some of the test the men are accused of negligently interpreting at a "negative test" of the well.

U.S. District Judge Stanwood Duval has yet to rule on an earlier motion to dismiss the seaman's manslaughter charges.  He heard those arguments earlier this month.