SAM DONELLY has been obsessed with the Titanic since his kindergarten days.

That's when the movie came out.

"He watched it until he broke the VHS tape," his mother, Jane Austin Younger, said. "He just loved the whole thing."

As a kid, he made models of the Titanic from Legos and spent his spare time researching the doomed voyage. Now 20, he's building a digital model of the Titanic and has a near-encyclopedic knowledge of the 100-year-old tragedy.

"It's just mind-boggling how much work went into [building] the Titanic - and how quickly it went down," said Donelly, a freshman studying criminal justice at Valley Forge Military College.

So when he first heard, a few years ago, that a British travel company planned a memorial cruise to the site off Nova Scotia where the "unsinkable ship" took 1,517 passengers to their watery deaths, he was totally in. And when he told his teachers and commanders at the military college in Wayne that cruise planners invited him to play dinner calls and "Taps" on his trumpet and bugle during the nine-day journey, they were in, too, giving him permission to miss two weeks of classes to represent the school aboard the Azamara Journey.

But, instead of coming home to the congratulations of a job well-done, Donelly returned to school last week with his head hanging with disappointment. He didn't get to memorialize Titanic victims after cruise planners told him that "Taps" didn't fit the memorial ceremony.

"I felt like they disrespected me and the song," said Donelly, who plays the funereal tune every Sunday as part of his school's weekly chapel service.

Younger, of Cape May, N.J., paid a whopping $48,000 for tickets for herself, Donelly, her daughter and her mother, and spent even more on period clothing to wear at sea. She was more blunt: "They're freaking moron wimps."

The cruise company, Miles Morgan Travel, countered that Donelly was never promised to play "Taps." Instead, general manager Claire Oliver said, he was invited to play dinner calls. "That was brilliant," Oliver said of Donelly's performance of "The Roast Beef of Old England," a traditional meal call. With regards to "Taps," his mother, about a week before [the ship set sail], said he could play 'Taps,' " Oliver added. "I told her we would discuss it onboard."

But planners decided against it. They'd been planning the voyage and memorial ceremony for four years and already had an orchestra lined up to play "Nearer My God To Thee," reportedly the last song that Titanic musicians played as the ship plunged into the North Atlantic Ocean.

"It really wasn't that relevant with a British ship going down on a British crossing," Oliver said of the American tune. After several passengers rallied on Donelly's behalf, planners offered to let him play before the memorial ceremony, but by then, Donelly was disgusted and demurred.

Back at Valley Forge's 100-acre campus, Donelly, dapper in his dress uniform, brought his bugle and trumpet to stately Mellon Hall Monday to perform for this Daily News reporter, who appreciates a damn fine American classic even if the British don't. Donelly blasted the mournful tune in the hall's small museum, reluctant to play outside lest he confuse cadets with the unprompted dirge as they strode to class.

Besides the musical snub, Donelly and Younger agreed that they had a great time on the cruise. "All-you-can-eat sushi was amazing, especially after coming from a mess hall," Donelly said.

And Donelly's favorite part: The memorial ceremony from which he was excluded. The Azamara and the Balmoral, a ship that embarked from Britain, sailed to the site of the Titanic's fateful iceberg collision and nearby, where it sank. At 2:30 a.m. on April 15 - the same time and date of its deadly dive - the brief memorial service was held on both ships' decks. At its conclusion, workers shut off all lights within sight, so cruisers could taste just a bit of the terror that the Titanic's passengers felt in the final minutes of their lives.

"I did imagine what it would have been like on the Titanic, looking out into the ocean that, 100 years [ago], on the same spot where I was standing, there was an 869-foot long steam ship that was sinking at a 40-degree angle and about 1,500 people were about to die in the ocean, and there's nothing around except compete darkness, the water was about 29 degrees and there was nowhere to go," Donelly said. "No one could hear you screaming for help. It was just in the middle of nowhere.

"The first thought in my head was, I really hope we don't run across any icebergs. The second thought was that it was probably the scariest thing that could have happened to anybody."

Contact Dana DiFilippo at 215-854-5934 or difilid@phillynews.com. Read her blog at phillyconfidential.com.