SELDOVIA -- Claws scuttle across pearly pink ground. Crimson tufts erupt from the ends of tangled white tubes. A wavering tentacle probes from behind a thicket of brown. Then — a monstrous crash.

A pudgy finger plunges into the pool, sending waves swashing through the thicket of seaweed. The limpet pulls back its tentacles, suctioning itself hard against the pink encrusting algae. The hermit crab pulls back its claws, rolling down the steep side of the tide pool in its borrowed periwinkle shell. Tube worm tufts zip into hiding.

"Don't scare all the tube worms!" my 4-year-old yells. "I want to scare some tube worms too!"

"It's OK," my 6-year-old replies, jabbing his finger across the small tidepool. "There are, like, a hundred tube worms here. It's tube worm world!"

A hundred tube worms cowed, we slither down into the cool, slimy crack between the rocks, placing our hands carefully on the jagged shells of barnacles. Curtains of ribbon kelp hide plump, purple sea stars and the drooping pendulums of Christmas anemones, their sagging flesh barely supported by the air. I snap pictures of the same anemones I've photographed every year I've lived here -- anemones that may be decades older than I am.

This is Seldovia's Outside Beach. We have an Inside Beach, too. There's also Sandy and White Rock, Schooner and Barabara, Hoen's, Jakalof, Wadsworth and MacDonald. Between them, we have beds of velvety sand dollars, lairs where the giant Pacific octopus hides, and cobbles sheltering a half-dozen species of quarter-sized crabs. I have filled my leaking Xtratufs, at least once, at every one of them.

When the tide book numbers turn to green, when those numbers dip to minus 3, 4, 5 ... we're there. In fact, the lowest spring tides will find us in a tent on the beach grass, coffee thermos in my hand, just waiting for that 10 a.m. low.

The kids I bring are only an excuse. Intertidal creatures are my own addiction. They've had a special place in my heart since 10th-grade marine science class, where I memorized their scientific names from a thick stack of hand-illustrated notecards. Strongylocentrotus drobachiensis. Tonicella lineata. Pisaster ocraceous. A few still pop to mind 20 years later. They're still relevant, even 1,500 miles away from my Seattle high school along the same convoluted Pacific coast.

Slimy and scuttling life

It's not actually true that Cook Inlet has the second biggest tides in the world (that honor goes to Ungava Bay in northern Quebec — Cook Inlet is fourth). But it is true that the tide moves as a wave, focusing and intensifying as it crashes into the Gulf of Alaska and funnels into the narrowing gap of Cook Inlet until, at Turnagain Arm, the flood becomes a breaking wall we can see.

Here, on the south side of Kachemak Bay, those big tides combine with rocky shorelines and clear water to shelter a phenomenal assembly of slimy and scuttling life. I've walked thousands of miles of shores, and I can tell you this: Seldovia has the best low-tiding.

I don't go low-tiding for the kids. But I stop for them. I stop my hurried splash past all the commonest things -- the stars and burrowing anemones and hairy tritons -- to crouch down with my 4-year-old, feeling the tacky pull of tentacles and tube feet, running our fingers over the sandy cases of worms. Gooey, sandy, slimy, sharp, rough, hairy, sticky, spongy, slippery, wiggly, spiny, soft and wet. Low tide is for touching.

Low tide has a sound. A hissing, squealing, whistling, popping sound of water disappearing. You can hear barnacles closing. Listen as the limpets and snails suction their moist bodies against the rocks. It smells like a breeze of salty decay. It tastes like gritty nori and sea lettuce plucked straight from the rocks.

My daughter chews a handful as we walk -- rock to rock across the now-flooding pools. Barnacles and snails crunch, inevitably, beneath our feet. Low tide has always been vulnerable to us. Sea urchins decimated so many kelp forests when Russian fur hunters killed off the otters that ate urchins.

Recovering otters work in concert with humans to decimate fat clams and the Dungeness crabs that scuttled here when my 38-year-old husband was a child.

Urgency of rising tides

Growing levels of carbon dioxide acidify the ocean. Along Arctic Alaska's Beaufort coast, the surface is already too acidic for shell-building creatures to thrive. Then there are the mysteries we don't understand. This June, the biggest toxic algae bloom ever recorded on the West Coast drifted into our waters. Over the past two years, a virus has turned sea stars up and down the Pacific Coast melting into puddles of goo.

Today, the purple stars seem, if anything, obscenely fat. The bidarkis are abundant, and the kids and I don't miss the crabs we've never seen. We've come not for food, but for treasure.

I love the lowest tides. They are a treasure hunt for the colorful, slimy, and strange -- for all the things that hide beneath rocks and scuttle into damp dark crevices. I love the infinite detail, the abbreviated urgency of the rising tide.

Low-tiding is a mesmerizing exploration of a few square feet, followed by a mad, scrambling dash when the water rises to the tops of my Xtratufs and chases me up the beach almost before I know it's coming. Then it's over. The kids sit where the water rises over their cuffs and boots, and they let it all go: a bucket full of dime-sized sea urchins, flapping gunnel fish, gliding nudibranchs and the seven common kinds of crabs.

We can see this much of the sea for only a few hours a month. It's precious and special in its rarity.

When sunflower stars glide around my feet, first curling and uncurling one arm, then another, their delicate tube feet tapping the seaweed in a rapid searching crawl, it's like watching my children playing together when they don't know I'm peeking. A glimpse into the magic of a world that doesn't include me.

Erin McKittrick is a writer, adventurer and scientist based in Seldovia. Author of "A Long Trek Home: 4,000 Miles by Boot, Raft and Ski" and "Small Feet, Big Land: Adventure, Home and Family on the Edge of Alaska." The latter won the Outdoor Literature category in the 2014 National Outdoor Book Awards. You can find her at GroundTruthTrekking.org.