His passion for riding the waves rates a close second to his passion for baseball.
"Surfing has always been part of my life, ever since I was a little kid," said the Mariners' left-hander, born and raised in Australia. "All my friends surfed."
They still do.
But with another season with the Mariners under way in Arizona, Rowland-Smith has put his surfboard away for the spring and summer, concentrating instead on his day job, which is trying to secure a position in Seattle's five-man rotation.
"I am trying not to think too much or set goals," he said. "I want to use Spring Training to get in good baseball shape and start the [regular] season off with my arm in great shape, to where I feel powerful.
"The only thing that matters to me when the season begins is my first start, then the next start and go as deep into every game as I possibly can. If I can do that, the numbers will take care of themselves. My only goals are to keep it simple and be consistent."
Sort of like riding a big wave, where staying calm is paramount to staying upright for as long as possible.
"Surfing is something I have always done for fun," Rowland-Smith said. "Surfing is good for you in many ways. It calms you down and is social. It's good to be out there with your friends, and it's good for your mind and body. It's unbelievable."
But does surfing help you in baseball?
"The jury is still out on that one," Rowland-Smith said. "Obviously, paddling is good for your shoulder strength. People have told me it's good for that, but I still wonder if surfing really helps that much. I am still trying to figure that out."
When it comes to having fun, some of Rowland-Smith's most memorable experiences occurred when he went surfing with family and/or friends along one of the many beaches near his Newcastle, Australia, home.
"I remember being a little kid, maybe 10 years old, living about 45 minutes from the beach and driving to Catherine Hill Bay with my older sister, Rhiannon, to go surfing," he said. "My sister is an amazing surfer. Always has been.
"The waves got really big there and I hated it, because I was intimidated by them. But Rhiannon loved it and my mom would drive us there on weekends to surf. My sister, who is four years old than me, would torment me because she knew I was afraid of the big waves."
"I am good with it now," he said, smiling, "but I remember being scared."
Facing Alex Rodriguez with the bases loaded and a three-run lead late in the game is a piece of cake compared to a six- or seven-foot wave bearing down on you.
Not to mention a shark or two swimming nearby.
"I've never seen a shark and never even thought about it until I came over here [U.S.] to play baseball and guys asked me about it," he said. "I guess they must have seen something on the Discovery Channel or something.
"Sharks were something we never thought about. But now I just put my fingertips in the water when I start paddling."
There were a few more chuckles when he talked about the 5 a.m. bike rides he and his buddies took to the beach to get in a couple of hours of surf time before school started.
"Even in the winter, we'd get up early, grab our stuff, catch a bus and surf for about two hours before going to school," he said. "It was freezing, but we didn't care. We wore full body suits.
"In the summer, we'd surf every day. It was the culture that I grew up in. Everybody I knew surfed."
But few of his friends were as good as his older sister. Rhiannon became so good that she became a professional surfer -- and still is.
"She's the best athlete in our family," Rowland-Smith said. "She was good at every sport she tried, but surfing was her specialty. The biggest wave I have surfed is probably six or seven feet high. She has done way bigger than that in competitions."
Rowland-Smith recalled going on a surfing safari with some of his older high school buddies and, being the youngest, he just had to take on the "monster" waves that were washing ashore on this particular day.
"I was probably 15 and they were 17 and 18," Rowland-Smith recalled. "They had a driver's license and we went camping one weekend at Camp Plumber, an unpatrolled beach. I will never forget it. The waves were way over six feet high. I had to go out there, or I knew I would hear about it in school."
He survived the weekend.
"It was a great experience for me," he said. "I overcame my fears."
Some 12 years later, he's still crazy about the sport.
"It's something I will do forever," he said. "I go home now, see some really old guys out there and think, 'Someday, that will be me.'"
"Oh, about 80; something like that," he said.
But long before that time comes, like at the end of this season, he wants to take a surfing trip with his sister.
"I've been checking out some places," he said. "Maybe Fiji, or Barbados. Those are great places for surfing."
Not the great northwest?
"I haven't seen too many waves around Seattle," he said, smiling, " but I have heard some good things about Sequim."
Jim Street is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.