Can a mother and daughter be happy participating in competitive sports together — and sometimes on opposite teams?

In the case of Chula Harrison (mother) and Kilia Hinrichs (daughter), the answer is yes. They share a passion for sand volleyball and surfing and, more often than not, they do both together. Sometimes they are on the same side of the net, sometimes they are competing. Sometimes they're paddling for the same wave, sometimes they're cheering each other in the surf.

Hinrichs describes their closeness as being not just a mother-daughter but also a friend-friend relationship.

"We're paddling out together and giggling about this and that or just being quiet, too," Hinrichs said. "We do so many of the same things. She's young in so many ways."

Of course, it's not always easy. There are some sensitivities. Do you go all out and do whatever it takes to win, or do you hold back a little when competing with your mother or daughter?

Hinrichs sees an upside and a downside to the family competition thing.

"You know each other really, really well and it's a huge bonus, like being in the kitchen together when you can move around each other and anticipate what the other person's going to do. Communication is easy," Hinrichs said. "The tricky part is if you're ever in a mood, or if there's stuff going on in the family. There's sometimes a little vibe, but it's easily remedied. Because we're also friends, we get past it."

The downside is deciding, when pitted on opposite sides of the volleyball net, whether to spike a mean shot or protect the family member. "If I know she's tired and I'm the stronger one that day, it's confusing because I want to hammer on her to win but I don't want to hurt her," Hinrichs said, a little sheepishly. "It's fun to win a game, but having a match where you play hard and there's great athleticism is way more important. If the competitiveness gets in the way of the fun, then to me it's not important. ... Don't go home and feel bad about what happened."

Harrison was gifted genetically with a slender, athletic body, and she has maintained it all her life. Her only concessions to her age are switching from volleyball four times a week and surfing two times a week to now playing volleyball two times a week and surfing four or five times a week. "The water is more forgiving than the land," she explained. Throughout a lifetime of athleticism, she has been fortunate to remain injury-free.

Another reason to envy Harrison: She swears she eats whatever and whenever she wants to, and always has.

Of course, exercising for three or four hours every morning does burn a lot of calories, not to mention toning the muscles.

One of Harrison's secrets is her attitude: "I don't believe that aging should limit you," she said. "I'm blessed that I have no injuries and no pain, and don't have a problem with balance. I don't feel that I'm aging."

In addition to becoming a mother, Hinrichs' life took a radical turn recently. Her husband was an Aloha Airlines pilot; he is now out of a job, and the family moved in temporarily with Hinrich's parents.

In characteristic upbeat fashion, Hinrichs sees it as an opportunity to work out with her mother on a daily basis.

More change is coming, as the Hinrichses expect to move to the Mainland or New Zealand. She may not be able to surf or play sand volleyball every day, but she's sure to maintain an active lifestyle.

It sounds like Hinrichs' son is going to be athletic like his mom and tutu. Hinrichs says that he can't tolerate sitting. "He's such a go-go-go kid that he's not OK with being in the stroller. He'll cry and yammer the entire time. But going to the park with him is fun," she said.

Not surprising. Harrison said all four of her kids and seven grandchildren surf and otherwise engage in sports. This is a family that stays together and plays together.