FOLLY BEACH — Newborn calves are side by side with the mother dolphin in the water, their fetal folds showing.

The boats never see them.

“People just whizzing past,” said Kathryn Stoneburner as she works binoculars from the dock at Folly Creek. “This is a huge area not only for dolphin to feed and socialize, but to calve.”

Boat strikes recently killed three adult dolphin, a dolphin calf and two sea turtles in Charleston area waters over the course of three days.

The worst part might have been that it really wasn’t anything too unusual for a busy summer weekend.

Biologists recover dead and wounded sea mammals and turtles throughout the season.

Stoneburner, a dolphin researcher, and others say casual boaters need a better sense of just how to operate motorcraft in Lowcountry estuaries where bottlenose dolphin, sea turtles and manatees swim near the surface.

Call it dolphin etiquette, a simple set of rules.

The bottom line is that no laws are in place except in federal waters, such as marine sanctuaries. The Marine Mammal Protection Act has laws against harassing the animals, but in the case of boaters they are nearly unenforceable.

But wildlife biologists and others say the etiquette is simple: Keep an eye out, use caution — especially at low tide, slow down and stay away.

“Basically, people are going too fast,” said Joe Walters, of James Island, who watched one of those dolphin struck trying to avoid a speeding boat in Clark Sound. It had nowhere to go in a narrow channel at low tide.

The dolphin floated dead onto the mud flat behind his home.

Walters said he has had to stop his boat as often as seven times for dolphin and calves at low tide while coming through that channel.

“It’s common sense (the dolphin can’t get out of the way),” he said. “But I don’t think a lot of people know it.”

Walters is now petitioning the S.C. Department of Natural Resources to place no-wake signs in the channel.

“I’m not the guy who jumps up and down and screams,” he said. “I just don’t want any more dead dolphin in my yard.”

Meanwhile, the John’s Island Conservancy is working to place signs along the Sam’s Spit inlet of the Kiawah River and to develop a set of guidelines to hand out to boaters.

One of the dolphin who died that weekend died there.

Stoneburner is doing field work for a singular National Ocean Service study of how dolphin respond to the noise and disruption of bridge building on Folly Creek and the Folly River. Dolphin communicate with whistling calls under the water.

The study, using a hydrophone, will be one of the first like it, showing how coastal development impacts dolphin, said Wayne McFee, of the ocean service.

Dolphin frequent the river and creek, particularly at high and low tides, Stoneburner said. As many as one in every 10 sightings is a mother and calf pair.

Stoneburner is monitoring the response to boat traffic along with that study. She has watched dolphin frantically deep dive to avoid a boat, or leap off to the side to avoid one as they surface.

“It happens all the time,” she said. “People really do need to pay attention.”

Reach Bo Petersen at 937-5744, @bopete on Twitter or Bo Petersen Reporting on Facebook.