The family of an Irish bikini designer found dead aboard a luxe yacht at a high-end New York marina is treading water after a federal judge put their state-level wrongful death lawsuit on hold while the boat's owner seeks exoneration or liability limited to less than 1% of their $50 million demand under maritime law.

Martha Nolan-O'Slatarra was a 33-year-old Irish expat and New York fashion designer – whom police found dead on a 54-foot Sea Ray named "Ripple" at the Montauk Yacht Club in August 2025.

The 61-year-old yacht owner Christopher Durnan, a multimillionaire insurance mogul and investor in the woman's summerwear business, has now turned to federal maritime law in a bid to avoid liability altogether — or cap his potential exposure at $476,942, which his attorneys said is the vessel's appraised value.

"This is a typical delay tactic that is rarely successful and will not be here," said Michael Bowe, a New York attorney representing Nolan-O'Slatarra's family. "Mr. Durnan will soon have to answer to the complaint we are prepared to file and then to sit for his deposition." 

James Mercante, an attorney for Durnan who specializes in maritime law, declined to comment.

Filings like Durnan's are common, according to David Cattie, an attorney based in the U.S. Virgin Islands and another expert on federal maritime law. He said vessel owners have "vastly more protection" at sea than on land, if the facts of the case meet federal criteria.

"But if they are claiming, and can prove, direct involvement or knowledge by the owner, those protections evaporate," he told Fox News Digital.

"In short, he is asking the Court to invoke admiralty’s jurisdiction to stop the state court claims," he said. "He is also asking the Court for exoneration, [the] owner has no liability at all, or limitation, which caps liability and exposure to the value of the vessel post incident."

The federal court battle will focus in part on what's known as "privity," he said — whether the circumstances that allegedly caused or contributed to Nolan-O'Slatarra's death involved something Durnan personally knew about or was responsible for.

"If the owner was involved in or knew of the defect that caused the harm, he cannot limit his liability to the value of the vessel," he said.

Even though the boat was docked in the marina at the time, it was still legally in what's considered a "navigable waterway," Cattie added.

"If the harm transpired on the vessel, it would be subject to Admiralty jurisdiction," Cattie told Fox News Digital. "If it happened on the dock and the deceased was moved to the vessel, it would probably not."

Durnan has denied wrongdoing and has not been charged with a crime, and his attorneys have denied any fault or neglect on his part.

According to his federal court filing, Nolan-O'Slatarra was a guest aboard the Ripple on Aug. 4, 2025. Around midnight on Aug. 5, she was unconscious and unresponsive, and Durnan attempted to render aid, according to the filing. Durnan's lawyers wrote that he sought help from people aboard other vessels at the marina. One of them called 911 and another performed CPR on Nolan-O'Slatarra.

"If any fault caused or contributed to the claims for loss, damage and/or fatality, which is denied, such fault, neglect, or want of care was occasioned and occurred without the Petitioner’s privity or knowledge," Durnan's lawyers wrote. "The Petitioner acted reasonably under the circumstances."

Although the wrongful death lawsuit was filed in August, Durnan had not been served with it until Oct. 1, according to court filings. He had not authorized his attorney to accept service on his behalf and could not be found at his waterfront home on New York's Long Island, another one in nearby Garden City, where they saw a Lamborghini registered to his name, or a third in Windham, New York, about 150 miles from New York City, according to Bowe, who represents the designer's estate.

Nolan-O'Slatarra's family faced a 120-day deadline to serve the lawsuit.

A process server eventually found Durnan at a fourth property — his waterfront vacation home in Lantana, Florida, where they found a Rolls Royce parked outside, according to court records. After a days-long stakeout involving multiple process servers and private investigators, Durnan was finally served, allegedly telling one that he "was surprised it took you so long."

The next day, Durnan turned to a federal judge with his petition to avoid or limit potential liability, court records show.

"When we have trouble serving someone, it's a red flag that something fishy is going on," said Randolph Rice, a Maryland-based attorney and legal analyst. "Ultimately, this maritime maneuver may give the defense a legal lifeline, but it's far from clear whether the argument will float with the federal court."

Durnan is invoking the same federal maritime law used by the owner of the cargo ship that struck Baltimore's Francis Scott Key Bridge in 2024 in an effort to limit its liability for the disaster, Rice said.

On Oct. 27, U.S. Magistrate Judge Gabriel W. Gorenstein approved Durnan's request to put up the appraised value of the boat as substitute collateral and ordered that related litigation "hereby are restrained, stayed and enjoined until the hearing and determination of this action."

He also gave Nolan-O'Slatarra's family a chance to dispute Durnan's request. The judge set a Jan. 25, 2027, deadline for potential claimants to enter the federal case and challenge Durnan's bid.

Town of East Hampton police arrived at the Montauk Yacht Club around midnight on Aug. 5, 2025, in response to a report of an unconscious woman aboard Durnan's boat. It was Nolan-O'Slatarra, who was pronounced dead at the scene.

According to Suffolk County police, forensic pathologists found no signs of violence, but her final cause of death was pending additional investigation.

However, in a wrongful death lawsuit filed earlier this year, her family alleged Durnan assaulted Nolan-O'Slatarra or otherwise engaged in grossly negligent, reckless and wanton conduct that caused her injuries and death.

"The EMTs, when they arrived, found blood in her mouth. On her chest, on her head, and they believe behind her, behind her head," Bowe told Fox News Digital in August.