TopKayaker.Net: Guide To Kayak Caving

All photos by John Gray unless otherwise noted.
Includes excerpts from "Sea Caves As I Know Them"

Smart kayakers are scared to death of sea caves. However, most of us - full of abandon and void of common sense - find caverns filled with salt water irresistible. Personally, I've never seen a sea cave I didn't enter - and I've traveled 10,000 miles to find them, and even designed a unique inflatable kayak to explore them called Sea Explorer. When my Asian sea cave survey was successful, I never went back - even to idyllic Hawai'i.

However, Asia's caves are so weird I didn't stand a chance of developing the art of "Tidal Sea Caving" without a decade of playing in Hawai'i's superb caves. I spent the 50's swimming and SCUBA diving into California kelp-filled caves, which I now find so boring they don't even count.

What follows are some recommendations based on that expertise with some insights into the variety of kayak caving adventures you may decide to pursue.

Tropical Sea Caving Hawaii Sea Caves Asian Limestone Caves Resources

Tropical Sea Caving & Tidal Surge

Haeng Toi Viet Nam

Any open ocean cave has special dangers. In intrusive dikes (wave battered fault lines that eventually grow into sea caves) most dangers come from the element that created the cave in the first place - surf.

  • Your Kayak

If you paddle short, high, wide open caves in calm water, a decked hard-shell is OK. However, I've found that for serious sea cave explorations, an extra-tough inflatable is essential. In an inflatable, I can lean from side to side, or lie down flat on the inflatable's floor and inch under a low ceiling handhold by handhold. When surf fills one of those "simple" caves with crashing foam that bounces your kayak off the rocks and sucks you into a whirlpool, I'd just as soon have the inflatable's stability and positive buoyancy.

  • Wave Surge

Bat Cave Thailand

If you don't already know sea caverns, never enter a cave if there's any wave surge, especially in a hard-shell. A sea cave is like a rock garden, except the visibility isn't so great. In even small swells, foam breaks against the cave walls, currents bounce into each other, and the place is generally a mess. In a small cave, confused waters automatically throw you into sharp rocks. If the cavern is big, the eerie sound effects often panic the inexperienced.

  • Sound Vs Sight

If you keep a cool head, rough rides in sea caves are survivable even if uncomfortable. Even with a strong dive light in an open cave, sound replaces sight as your primary sense. When entering a cave, always listen behind you. An unnoticeable swell on an open beach can create a six-foot crest deep down inside that long funnel.

Penak Over Hang Thailand

A "big" swell in the back of a 100 meter cave can be very exciting. Every cave has its gurgling monster noises in the back, but a large block of water plummeting into a narrowing cave sounds like a freight train coming at you. It is a sound you never forget.

If you can still see sunlight in the mouth of the cave, watching doom approach can be beautiful. When the water rises, that reassuring ray of light becomes grotto turquoise. If it turns deep green, watch out - the wave is unusually thick. You are going for a rocking chair ride in the dark that may instantly throw you three meters straight up.

  • Look Up

Learn to "look up". I always look for a high ceiling. Its scary back there, but the hydrodynamics are similar paddling through surf. Of course, the wave still breaks in the back of the cave - hopefully on a gravel beach. If you can keep your kayak straight to the wave, you might not log roll. Stay away from the beach in the back where the wave crests and breaks in the dark and you won't wipe out. Find a spot with a high ceiling and you won't slam into the roof as the wave passes by.

  • Turn Into The Surge

Turn into the wave as it comes. It isn't essential to face it, but take the wave straight on with either your bow or stern. Basically, you're riding over forming waves. It just dark and narrow. Practice this routine in open surf, inching your way slowly to the beach, feeling the waves form behind you as you rock over their crests. It's much easier paddling out from the beach with the waves before you - same inside the cave.

Unfortunately, Murphy's Law of Sea Cave surges says the blockbusters only come when you are entering a cave, i. e., they are at your back. Whatever you do, once you hear a wave coming, don't try to turn around to face it, especially in an unfamiliar cave. It's almost impossible to "180" a kayak rapidly inside a cave. The worst thing you can do is take the wave broadside and log roll. Side-surfing is almost impossible in the dark. You'll probably catch your bow or stern on a protruding rock anyway.

Surf kayakers knows the thrill of breaking through a cresting wave just as it breaks. There's the thrill of going almost vertical as you power up the face, the relief of punching through, and the report of going airborne and slamming down on the back of the wave. The same dynamics occur at the back of a sea cave, except you are in the dark and narrow. Combine the sound effects, close and unfamiliar quarters, extremely vertical wave faces and total darkness and you can feel free to insert "terror" for "thrill".

Kikipua From Haka'a'anoHawaii's Sea Caves

There's one small, long irresistible cave in Ha'upu Bay, Moloka'i, a 100-metre narrow funnel just wide enough at the back to turn a kayak around. Mrs. Murphy always sends an untimely swell just when I'm at the back. Once, I was literally on the gravel beach, and foolishly tried to turn the kayak around. I was dumped sideways. A few times I've powered up a vertical face to punch through a cresting wave. These experiences were never fun. If you do dump, fate rules. If you avoid eternal darkness, lucky paddlers get spit onto a gravel beach without to any large rocks. You're still alive, but it's a real mess getting you and a swamped boat out of there before the next wave hits.

Some caves are really tunnels, open at both ends. Invariably, these guys are big, with more light and less turbulence since the water doesn't back pressure. Even so, I wouldn't want to be in the confused waters of Moloka'i's "Jaws of Death" in anything but my Sea Explorer. Even in summer, six-foot swells pile into its mouth, agitating the waters before you turn inside the tunnel. One-meter haystacks crest two meters apart. In an inflatable kayak, it's a fun ride, but I wouldn't want to go for a swim.

Surf creates lava and granite caves only as far as wave action penetrates. Facing directly into Hawai'i famous ten-meter surf, tunnels on the North Shores of Moloka'i and Na Pali are 150 meters at the most. In limestone, less dramatic but constant tidal action creeps hundred of meters, in some cases' kilometers, deep into the cliffs. Waves are still a problem at the smaller entrances. However, where the brute force of water power is the dominating factor in the Western Hemisphere, the subtle complexity of Asia's limestone has its own set of dangers.

Asian Limestone Caves

South-East Asia's tropical waters are filled with limestone islands, and limestone means caves. Unlike the simple surf-battered sea caves of North America and volcanic Polynesia, Asia's caves can extend for miles, with complex stalactite-filled off-branches, high ceilings and low overhangs that open and close with the tides. Beyond the openings of limestone caves, the water is always flat. However, this flat water has its own set of dangers.

Many caves are merely entrances to inland tidal lagoons. In tropical Asia, spring tides change as much as two feet an hour - an inch every two minutes. Large volumes of water funnel through the caves, "boiling" over submerged rocks and forming midstream whirlpools. The current moves as fast as a mountain stream, complete with sound effects echoing off the cave walls. I body surf Waimea Bay, but I could not swim in many of these caves.

Lau Gudu ThailandBecause the caves are so small, time inside the lagoons can be measured in minutes, and only at precise tidal levels. Until a paddler learns a cave, the kayak frequently bounces off submerged, irregular oyster encrusted rocks. A stock inflatable is ribbons, hard-shells roll and a swimmer is hamburger in these fast, dark rivers. Limestone caves are noted for delicacy and complexity, and Asia's caves are no exception.

Some giant caverns have tiny "windows of opportunity", exact points on the tide chart when a kayak can pass. In many cases, the kayak barely squeezes through. We lean far to either side, or lay flat on our backs in the floor of the Sea Explorers. Like a mechanic on a "creeper", the Sea Canoe Team inches our way through these windows, often with the roof mere inches over our noses. We can see the rocks just above our eyes, but we feel our way into the unknown, squeezing our reinforced bows into every small hole we can squeeze into. This is no place to discuss the fine points of paddling rotation.

The body language is worth the effort. Beyond these small "windows", caverns can be three-dimensional, with fifty meters ceilings, formed by chimney-like "swallets", rainfall drainage tubes that run from the top of the island.

Frequently, a second "upstairs" cave parallels the sea cave. These "over-under" caves formed a few thousand years ago when the sea was 3-5 meters higher. Frequently, the roof between the caves collapses. Stalactites from one inch to thirty meters appear deep inside these sponge-like islands, forming columns of crystallized sparkle in your flashlight beam.

Into Koh Bele HongMany of the longer limestone caves are entrances to cliff-lined inland tidal lagoons, called "Hongs" in Thailand, which means "room". The largest inland lagoons we know, in Vietnam, are up to two miles in diameter. These lagoons hold vast amounts of water that funnels in and out of the caves with the changing tides. Our Vietnamese guides tell us that fishermen swimming near the entrances on rising tides are sucked into these caves. It isn't a pleasant thought.

Some of Vietnam's lagoons are accessed by caves so large Vietnamese locals paddle small boats into the lagoons. Others, especially in Thailand, are served by smaller caves never entered before the Sea Explorer was invented. The Magic inside these cylindrical enclaves is from a time before humans walked the Earth. Discreet ecosystems develop, complete with natural "bonsai" trees and gigantic shellfish.

Visit John Gray's Sea CanoeJohn "Caveman" Gray started tropical kayaking in 1983 & currently runs a guide service out of Thailand called John Gray's Sea Canoe. Lava sea caves highlighted Gray's Hawai'i trips, and the 1985 "Moloka'i's Forgotten Frontier" documentary won an Emmy, the first of many Awards. In 1999, National Geographic Adventure named Caveman's SeaCanoe Vietnam itineraries a World Top 25 Adventure. You can read more of John Gray's adventures & conservation projects, as well as view his excellent photos at John Gray's Sea Canoe

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Index To Kayak Caving - Provides links to all our articles, including those below, for the kayak caving enthusiast.

Exploring Caves By Kayak by Tom Holtey
Tom discusses Sea Cave safety and prerequisites for enjoying this exciting aspect of sea kayaking.

Sea Cave Basics by David Bunnell - Dave Bunnell has explored and surveyed over 500 sea caves, and written two books on them. Here he gives kayak cavers an overview with great photos and links to more information.

Basic Surfing Techniques - Contributed by the British Canoe Union Surf Committee. This is a beautifully done manual on surfing maneuvers Originally published at The Watershed-UK.

Designing A Kayak For Caving - John Gray's story of the development of his signature Sea Explorer inflatable for kayak caving.

John Gray's Sea Canoe - You can read more of John Gray's adventures & conservation projects, as well as view his excellent photos and sign up for one of his trips.

TopKayaker.Net's Surf Section - Visit all our surf articles for helpful advice.

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