Tug pilot Matt Devlin of Catskill, N.Y., was consumed by a family emergency and had moved to a lower wheelhouse, where his view of the Delaware River was obscured, according to the information and plea documents filed Thursday.
In about 2 1/2 hours at the wheel, Devlin made and received 21 cellphone calls and also surfed the Internet on a laptop, investigators found. Devlin "went numb" after learning his son was having trouble waking up from minor eye surgery and had perhaps been deprived of oxygen, his lawyer said.
"You think your 5-year-old baby is going to be brain-damaged, or going to die," lawyer Frank DeSimone said, speaking publicly for the first time about Devlin's actions that day. "He couldn't think and he couldn't make decisions."
The charges come just weeks after the National Transportation and Safety Board issued its findings on the July 7, 2010, crash.
At a public hearing, NTSB officials stressed that the nation risks a surge in deadly accidents unless it makes distracted driving - talking, texting and surfing online while operating cars, boats and trains - as taboo as drunken driving.
Devlin was on his cellphone for 10 of the 12 minutes before the crash and could not see the stalled duck boat for the final nine minutes because it was in his blind spot.
Investigators believe the lower wheelhouse offered him more privacy and less noise to use the cellphone and laptop, both violations of company policy. DeSimone said Devlin used the computer to research the effects of oxygen deprivation.
"He's only going four miles per hour down the river. He didn't think anything was going to happen. He's done it 1,000 times," DeSimone said. "Had he been thinking clearly, he would have gotten relief."
Investigators believe he was talking to his mother when the crash occurred. He had talked to his groggy son a few minutes earlier. His employer, K-Sea Transportation Partners, told investigators he would have been relieved by the captain had he disclosed the emergency.
"Devlin was either talking on the cellphone to family members, or reviewing Internet searches, virtually continuously from 2:01 p.m. until the accident happened at 2:37 p.m., that is, during the entire time that the duck boat was moving and then halted in the Delaware River," the plea memorandum stated.
The 250-foot barge ran over the 33-foot duck boat, sinking it and sending all 37 people aboard into the busy shipping channel. Some survivors found themselves trapped under the barge in the dark water and had to feel their way around it to escape.
The bodies of the Hungarian students, 16-year-old Dora Schwendtner and 20-year-old Szabolcs Prem, surfaced in the days that followed. They attended the same high school in northwestern Hungary and were visiting the United States through a church exchange program. Both were described as experienced swimmers.
Devlin has agreed to plead to one count of misconduct of a ship operator causing death and to surrender his Coast Guard license. He faces 37 to 46 months in prison under federal sentencing guidelines, but DeSimone will argue for a sentence without prison time based on the circumstances. No plea date has been set.
"It's a tragedy," DeSimone said. "He's just devastated. ... He's a father, too. He loses sleep over it. He has nightmares over it."
Devlin's son has since recovered.
Duck boat Capt. Gary Fox, 59, of Turnersville, N.J., had turned off his engine on the 103-degree day after noticing smoke and fearing his engine would catch fire. Investigators found that mechanics who inspected the boat before the tour had failed to see that a pressure cap was not sealed properly, causing the engine to overheat.
The NTSB faulted Fox for failing to have passengers don life jackets after he dropped anchor, failing to teach them earlier how they should be worn, and failing to call the Coast Guard directly. His calls to Devlin, meanwhile, went unanswered.
Fox voluntarily surrendered his license after the crash, officials said. His license remains under administrative review, Coast Guard Capt. Todd Gatlin said.
NTSB investigators found that both companies - K-Sea of East Brunswick, N.J., and Ride the Ducks of Norcross, Ga. - had strong safety cultures, but that their training was not always followed.
K-Sea declined to comment Thursday on the charges against Devlin. Ride the Ducks said the criminal charge speaks for itself.
The students' families have filed wrongful-death lawsuits against the city, the operators of both vessels and others. Their lawyer, Robert Mongeluzzi, said the families are grateful that Devlin is being held accountable but called on the companies involved to "acknowledge their roles and act accordingly."
Ride the Ducks resumed its operations on the Delaware River this spring.