Newport Beach Fire Department Battalion Chief Jim Turner worked with Cross as a seasonal lifeguard, and said he was a
"great guy" and "an excellent waterman and avid athlete."
On occasion, Cross would "pop in and say hello" at lifeguard towers when riding his bike on the beach, Turner said.
"There's no reason to think he had a boating accident," Turner said, noting that Cross disappeared on a clear day without choppy water conditions or big waves.
"It was a beautiful day," Turner said. "He probably did that hundreds of times."
Glen Lindenstadt said he knew Cross since his early teens, and that his disappearance is a mystery.
"He lifeguarded the toughest beaches in Newport, and later found himself a supervisor in the unit," Lindenstadt said, adding that the missing man "loved being around the ocean."
According to Lindenstadt, Cross was an All-American swimmer at Orange Coast College in Costa Mesa and worked as a middle school science teacher in Garden Grove.
"If he wanted to, he could swim to Catalina and back; he was that much of an ocean guy," said John Brick, a longtime friend of Cross. "The guy's been in and around the water his entire life."
Meanwhile, Newport Beach police are investigating Cross' disappearance.
"The investigation is exploring all available avenues, including interviewing family and friends," said Newport Beach police Capt. Craig Fox, commander of the detective division. "To date there have been no suspicious circumstances discovered surrounding his disappearance, and as of this time, Mr. Cross and his kayak are still missing."
A 52-hour search for Cross — covering 2,446 square miles by water, helicopter and airplane — yielded no signs of him or his green kayak, the Los Angeles Times reported Sunday.
Cross' car was found near an end street on the Balboa Peninsula, according to Sgt. John Hollenbeck of the Harbor Patrol.
Despite his nine-day absence, Turner said he's still optimistic for a positive outcome.
"I am hopeful," Turner said. "I'm don't know what happened, and I hope it turns out well."
Anyone who has information about Cross' disappearance is asked to call Det. Ryan Peters at (949) 644-3779.