Professor Drowns While on Diving Expedition : San Miguel Island: Friends say the USC educator was an expert swimmer. Investigators aren’t sure what happened while he was submerged in 35 feet of water.

A longtime USC professor drowned off the coast of Ventura County on Wednesday during a diving expedition.

Willard Van Tuyl Rusch, 58, who friends described as an expert swimmer and diver, was pronounced dead at 10:10 a.m. at Los Robles Regional Medical Center in Thousand Oaks, where a Coast Guard helicopter took him after the 8 a.m. incident, officials said.

Coroner’s investigators were unsure why the Pasadena man ran into trouble while submerged in 35 feet of water at Wycoff Ledge, a spot favored by advanced divers off the southern coast of San Miguel Island.

Investigators had not examined Rusch’s equipment for possible failure because the dive boat, Peace, did not return to Ventura Harbor until late Wednesday. An autopsy ruled out the possibility that Rusch suffered a heart attack, Deputy Coroner Craig Stevens said.

“We’re still missing pieces of the puzzle,” Stevens said.

The coroner’s office will enlist the help of a diving expert to determine if a malfunction of Rusch’s equipment was responsible for the accident, said Deputy Coroner Mitch Breese, who was at Ventura Harbor when the dive boat returned.

Rusch and 21 other divers were at the island, the northernmost in the Channel Islands chain, for a day of pleasure diving when Rusch signaled to his partner that he was in distress, Coast Guard Petty Officer Scott Wasserman said. The partner, Steve Lewis, tried to grab Rusch and bring him above water, but lost his grip and watched helplessly as Rusch sank to a depth of 90 feet, Wasserman said.

At 6 feet, 4 inches tall and 220 pounds, Rusch may have been too heavy for his partner to carry, Breese said.

By the time the divers got Rusch up on the boat about three or four minutes later, his heart had stopped beating, Wasserman said.

After returning to Ventura Harbor, Lewis said he did not know what caused Rusch to signal for help minutes into the day’s first dive. “He lost his regulator and passed out,” Lewis said.

As his wife, Verna, consoled him, Lewis shook his head slowly. “I don’t know what happened to him,” Lewis said repeatedly.

Aluizio Prata, a former student of Rusch’s who dived with him the last two years, said Rusch died doing what made him happy.

“He was a very good, experienced diver,” said Prata, who also teaches electrical engineering at the University of Southern California. “But it’s a dangerous sport.”

Rusch had been a professor in electromagnetism at USC since 1960, said Hans Kuehl, a friend and chairman of the department of electrical engineering. He taught a graduate-level class in advanced electromagnetism and was an expert in the field of reflector antennas, which are used for satellite communications. He wrote a textbook on the subject, published in 1970, that is still used, Kuehl said.

Rusch, who directed the honors program for the School of Engineering, was well-liked by students and staff, Kuehl said. “He was always in a good frame of mind. He was very popular with the students.” Kuehl said Rusch is survived by his wife, Joann, and four children.

Kuehl said he was mystified by Rusch’s death. He said Rusch had been diving for more than a decade and swam every morning at one of the university’s pools.

“He was in very good shape,” Kuehl said.

Rusch went on expeditions to the Channel Islands and other spots at least once a month, Kuehl said, adding that diving was his passion.

Indeed, Rusch’s answering machine message at his USC office ends with the statement, “As far as I’m concerned, I’d rather be diving.”