Ask yourself this: Has the shark come and, if so, has he come for you?

We were surfing in Ventura recently. It was overcast, the waves were small and were being recast by a sideways chop rolling from the south. Having fled 105-degree Bakersfield, “overcast, small and a sideways chop,” while not ideal for surfing, seemed miraculous.

We were on stand-up paddleboards, which are big enough to float grownups. Armed with carbon fiber paddles, riders are able to propel themselves into waves.

“Did you see that?” my friend Harry asked.

Harry was standing on his paddleboard a few feet away from me and was looking down intently.

See what? I didn’t see anything other than a wave I hadn’t caught and Mike, another paddleboarder, who had caught it instead.

“I saw a shark,” he said.

A shark. A shark is a conversation starter. A starter and a stopper.

A shark is an eraser. It erases whatever conversation came before it and whatever attitude preceded it. A shark is like a famous preacher ready to deliver a sermon: Everybody holds their breath and has their eyes on the pulpit.

Surf etiquette dictates that the person who sees the shark reports the sighting to his or her companions. This can be useful information or the oldest trick in the book.

Telling people you saw a shark is the quickest way to clear a break and have it to yourself.

“How big was it?” I asked.

“How big” was irrelevant. Sharks are like bears. Even the small ones are bigger than you want them to be and a big one will have you doing a load of laundry before you know it.

“Six to eight feet,” he said. “I’m not sure because it was underwater.”

Underwater, because I’m about to walk on water. Walk on water. Just like in the Bible.

“And when the shark cometh — a six- to eight-footer — he left his companion — a dear friend — but a more promising meal, and walked on water all the way to the wet sand and then over the mountains and home.”

How big was it? When you couple magnification with imagination, a four-foot sand shark can turn into a 30-foot great white with wings.

“Could you see what color it was?”

In other words, was it whiter than the cake we served on my mom’s birthday?

That’s the second rule of surfing etiquette: Use the word “shark” sparingly, if you must, but never the words great white shark. Not while you’re in the water in the Great White Hotel.

“I saw another shark last week,” said Mike, who, after catching that last wave, would have been my choice for the catch of the day should I have been the menu consultant.

“The shark last week was a juvenile,” Mike said. “It’s been pretty sharky here.”

“Sharky” sounds sort of fun, and describing the shark as a juvenile renders it less lethal. How dangerous can a juvenile be?

How dangerous? If you’ve had teenagers, dangerous. Dangerous, unpredictable and usually hungry.

The four surfers sitting close to us paddled in immediately. I would have joined them if, rather than standing on the board, my legs were dangling in the water, which is shark-ese for “I am a seal. Come and eat me."

Mike left too. He’d read the kelp leaves. His last wave was good and things could only go downhill from here.

We stayed — we’re from Bakersfield and we don’t know better — but there was another reason. Another reason other than dumb. At least for me.

Everybody has a “shark,” with their name on it. When it comes, it doesn’t matter if you’re on dry land at a family barbecue, drinking margaritas — you’re done.

Until then, enjoy the show. You could be thrown in a shark tank with a rib-eye strapped to your arm and you’d probably survive. Armless, but you might make it.

We caught a few more waves. We forgot the shark. The monster with wings and teeth as long as slats on a white picket fence.