The most serious hazard for sea kayakers on exposed coasts is surf – most kayakers aim to spend as little time as possible surf kayaking. Loaded kayaks are not really suited for riding breakers. Helmets should be worn in the surf zone.
True surf kayaking is a different sport, with different boats, different rules, usually different people, but with useful tricks to learn. Surf kayakers can teach how to judge a wave from seaward.
There are three types of surf – plunging, spilling, and (rarely) surging breakers. Dumpers or plunging breakers are the worst and should be avoided where possible since they can smash your boat against the sand.
Spilling breakers have no explosive qualities as they first break – the ideal wave has a crest that collapses well out from the beach, gradually spilling its energy on its way to the land.
Surf seldom breaks evenly on a beach. There will usually be a quieter spot at one or both of the ends of a crescent-shaped bay as a result of the refraction of waves hitting the beach obliquely.
Prefer sand beaches but still watch for submerged rocks. Beware areas where the dissipation of the soup occurs before the wave reaches land. The smooth area may indicate a rock or coral shelf with a very shallow layer of water over it.
The steepness of the beach may be the most important. Waves forming over gently sloping beaches release their energy over a longer period. They rise gradually so when they start to break they have some foam forming just at the top then gently “spilling” down the face. In steep “dumping” beaches, the wave quickly peaks up over an abruptly shoaling bottom, curls over itself and explodes, releasing its energy all at once. Most beaches are a mix between the two extremes. The shape of a beach and the waves you find there can be dramatically different with changes in tidal height.
Reef breaks with spilling waves are good. The water after the reef is deeper so one is not as likely to hit the bottom if one gets rolled. Playing on a reef break requires a good roll to avoid long swims if one gets out of their boat.
If there is kelp or a reef off the beach, the waves will be broken in the lee of this and you can probably sneak in behind them.
Boat design affects the ability to surf. Touring kayaks tend to have a high length-to-width ratio, sharp vertical ends, and a creased keel line, all features that help with tracking but also make the bows plow beneath the wave, resulting in endos and broaches. A low cockpit coaming at the back allows weight to shift back to keep the front end from diving. A high-volume bow and a lot of rockers helps keep the bow up. A flatter bottom (rather than rounded or V-shaped) improves maneuverability on the wave.
It is important to not use skegs or rudders in the surf.
OUT THROUGH IT
Choosing an appropriate launching site is critical. A safe, low-energy site will usually have a gently sloping beach, fine sand, small spilling waves, few people, and no obvious obstacles or hazards. Looking at the size of the sand can give an idea of the wave history of the beach – the larger the sediment, the stronger the energy.
Put rudder up and secure any deck items.
1. Time the waves and count the sets of big ones. There may be three big waves then two small ones, followed by five medium ones – or some similar pattern that will enable the prediction of easier waves.
To avoid getting left high and dry or swamped, watch several waves and see how far an average wave washes up the beach. When you see another set of average-sized waves coming, drag your boat down to the same height.
Take advantage of a rip current if present (opening in a sand bar?).
2. Less experienced paddlers go first. If there are two helpers, one helps attach the back of the spray skirt while the other holds the bow into the incoming soup. When the timing is judged to be right, the person holding the bow pulls the boat past him giving a mighty push into the breakers, while, at the same time, you paddle as hard as you can, gaining enough momentum to punch through the wave. Continue to paddle with a strong, steady rhythm until you are well beyond the line of the surf.
3. If traveling solo or you are the last boat, to avoid getting left high and dry or swamped, watch several waves and see how far an average wave washes up the beach. When you see another set of average-sized waves coming (no lulls or big sets), drag your boat down to the same height and sit on the back of your cockpit. The next wave should reach your feet without floating your kayak. Keep your feet out to keep from washing out to sea prematurely. Wash the sand off your booties in the backwash and then climb in and secure your spray skirt before the next wave comes. If you are lucky, the next wave should float you enough so you can reach deep water with some gorilla grunts.
This is not easy with a loaded boat. Watch where you put your hands to avoid cuts on rocks. It is also easy to break a paddle when launching in this manner. The dissipating wave may slue and strand you sideways, exposing your beam to the next wave (rock the boat onto its side and spin it on the sand to face the next wave).
Wait in the soup zone for a lull to sprint out between sets of waves. Momentum is the key to getting outside, so paddle hard. For waves that are chest high or smaller, reach over the back of the wave and pull your kayak through. For larger waves, try to meet the wave either before or after it breaks. Build up as much speed as you can and then tuck forward and sit with your paddle off to the side. As you pass through the wave, paddle forward to keep your momentum going. Waves can take longer to break than you think, so it may be better to go for it than hesitate and have it break on your head. When in doubt, stroke it out.
Once you have made it outside, make sure you really are outside by paddling another fifty yards or so before you catch your breath. Set up several ranges to pinpoint your position both up the beach and off the shore.
IN THROUGH IT
A. Forward is usually the easiest way to come in through surf, but not necessarily the safest in a heavily loaded kayak. After making sure the beach is clear of obstructions, going forward involves considerable commitment but is quick avoiding time spent in the danger zone.
1. It is best to ride on the back of the wave avoiding the crest. By paddling backward and forward as needed, you can stay balanced on the forward edge of the foam pile, paddling straight up the beach with the surge, and hop out of the boat.
Paddlers on land signal with their paddles to either “paddle forward”, “stop”, or paddle backward. In this way, it is possible to avoid breaking waves.
Once the wave is caught, to ride it, it is important to know when to lean forward or backward in response to water dynamics. If you’re trying to catch a wave and it looks like it may pass under you (your bow is hanging over the face rather than sliding down it), try leaning forward as much as you can while still paddling hard. This may be enough to allow you to drop down the face. If the face is steep and your bow starts to bury in the trough, lie back as far as you can to keep the bow high in the water and prevent a broach.
To stay straight and surf ahead of the wave, continue leaning back while doing a stern rudder on one side or the other while edging up on the opposite side. These two equal but opposing forces act in concert to enable you to keep moving straight with the wave’s line of travel.
Practice in the soup zone where the already broken waves have turned into lines of foam. The foam piles are very ridable and a perfect place to practice. Catching these waves requires the same sort of timing used for unbroken waves but with no worries about waves crashing on you. Once comfortable with riding broken waves you’ll acquire the timing to take on larger, more challenging green wave faces.
2. When waves are over 4 feet, wait offshore and count the sets of big ones going in (usually three). Wait till a big set is on its way, then hammer in behind the last one, casting occasional glances over your shoulder to watch the next set building. Doing sprint speed usually gets one past where they are breaking. As waves travel much faster than your kayak, you will still need to deal with whitewater.
When you hear and see the leading breaker of the following set, let it get within 20 yards, then do a right rudder to get into a broach position parallel to the breakers. Lift paddle into a high brace and lean into the breaker as it hits. It carries the kayak in front, sometimes high up on the face, but more often on the smooth water immediately in front of the breaker. By going in at 90 degrees to the beach on steep waves, the bow digs in just as the wave caps, and the boat executes a graceful loop.
When entering sideways through the surf, it is essential to lean seaward – “Butt to the beach”. Remember that as much water is moving out to sea as is moving in. As soon as you edge into the land, you immediately capsize as the edge of your boat catches the outgoing water. With the boat tilted into the wave, keep your head centered over your boat using a J-lean to keep your edge up and your boat balanced, stabilize yourself with a brace and enjoy the ride. Too much weight on your brace will cause you to fall into the wave as the foam pile subsides.
This is a free ride as the wave does most of the work. Also, this is what usually happens anyway.
B. Backward. This is useful on unknown or marginal beaches since you are pointed the right way to get out fast if you have to. This is not recommended for crests in excess of 2 meters or for dumping breakers.
Once you have chosen an apparently clear path of entry, turn the bow to the incoming waves. Raise the rudder or skeg. Paddle in backward. When the cresting wave approaches, paddle hard into the wave so that the boat gathers enough momentum to prevent being swept backward at great speed. As soon as the wave passes, back-paddle quickly again until the next wave is almost upon you, and then repeat.
The problem is that it leaves you in the danger zone longer and you can take a hammering. Look over your shoulder frequently to judge the distance to obstacles and the beach.
C. Swim. Last-ditch for when you must get through exceptionally heavy surf with your equipment dry and intact. This landing increases the chances of gear and bodily damage particularly if you get between your boat and the shore. The beach must be clear of obstructions. You must be a strong swimmer. Use a helmet and ideally a mask and fins and go over the side. Collapse paddles, stow them inside, seal the cockpit, and head in stern first pushing the boat ahead as you swim into shore. Don’t wrap your hands or fingers around grab loops or deck lines. Holding onto your boat in the surf zone is usually not as crucial as in open water and can be downright dangerous in bigger breakers. Take care to never get downhill of the kayak, a position that can be lethal in the grip of a big wave. If you become separated from your boat, it will usually find its way to shore before you do.
To hitch a ride on your boat or another boat as it side surfs in, hold onto the cockpit or hull and ride it like a boogie board. Empty the water by rolling your boat upside down or using the flip and Flip and Drip method before you drag it up the beach.
Never land in heavy surf on a rocky shore.
Bull kelp can make a fine natural anchor, especially as dark approaches. Bet behind a dense mat of kelp, drag the kelp into bunches, and lash firmly. Haul more long fronds over the decks so that the boat is held fast.
ROGUE WAVES
Enormous ‘rogue waves’ can appear out of nowhere. Math is revealing their secrets. Once considered a maritime myth, these towering waves can pose serious risks to ships in the open sea. Now scientists are developing ways to predict them before they strike.
Scientists have recognized rogue waves as real phenomena since the mid-1990s—but keeping sea travelers safe from them is still a major challenge. Though they are relatively rare, rogue waves can cause severe damage and loss of life if they hit a ship in the open sea. In the vastness of the ocean, the interaction of the many forces leading to rogue waves can be difficult to untangle. More recently, mathematicians have been combining real-world data collected from monitoring buoys with statistical models to understand what causes these gargantuan waves to form. Their work offers hope that we may even be able to predict rogue waves before they strike.
How waves can grow
As shipbuilding technologies advanced in the 20th century, the number of surviving witnesses to rogue waves grew. In April 1966 an Italian cruise ship called the Michelangelo met with an 80-foot wave that rose high above the storm-driven waves around it. The ship sustained significant damage and three people were drowned, but most who were on board made it safely back to shore.
The crew aboard the MS München, a German container ship, weren’t so lucky. In December 1978 the ship left the German port city of Bremerhaven for Savannah, Georgia, packed with steel cargo and a crew of 28. After reporting bad weather and sending out distress signals in the early morning hours of December 13, the ship and everyone on it disappeared. A lifeboat that had been attached to the ship about 65 feet above the water was recovered, but it appeared to have been ripped from its post, likely by a towering wave at least that high.
Scientific doubts about these mysterious, giant waves were not completely dispelled until 1995, when a rogue wave hit the Draupner oil rig, a natural gas platform in the North Sea off the coast of Norway. The wave’s peak, measured by a laser detector on the rig’s scaffolding, rose 85 feet above the surface.
Scientists have since figured out that unlike tsunamis, which are large waves produced by a sudden displacement of water from an event such as an earthquake or landslide, rogue waves form due to a chance combination of wave movements through the ocean.
Two main mathematical theories have emerged to explain the wave movements that spawn rogue waves: Linear addition and nonlinear focusing. Linear addition assumes that waves travel through the ocean at different speeds, and when they overlap, they can strengthen into a rogue wave. Nonlinear focusing assumes waves travel in groups and can lend energy to one another, which sometimes spawns a rogue wave.
One reason for the uncertainty is that rogue waves are rare. Even now, there’s a dearth of quality tracking data.
“Generally ocean rogue waves are measured from platform measurements or buoys, which record time-measurements at a specific location without any knowledge of what happened before or will happen further,” says Amin Chabchoub, a wave physicist at the University of Sydney in Australia. A 2019 study led by Chabchoub evaluated several rogue wave observations and models, and the team concluded that the inciting rogue wave mechanism can change depending on the varying factors in the sea at a given time, known as the sea state.
To compensate for limited observations of rogue waves, scientists rely on wave tanks. “Recreations in a laboratory mimic almost one-to-one what happens on the ocean surface,” Chabchoub says. These experiments can even account for currents and winds, although the controlled settings have their own limitations.
When water is trapped in a narrow channel such as a wave tank, it’s much easier for large waves to form and to be observed. However, these experiments represent an “unrealistic scenario” because waves cannot spread in all directions as they would at sea, says Francesco Fedele, an ocean engineer at the Georgia Institute of Technology.
The National Oceanic and Atmospheric Administration is developing a system that can forecast potentially hazardous areas of the ocean every hour using a program called WAVEWATCH III. The latest version, released in 2019, uses a probability formula that Fedele developed in 2012 to predict extreme conditions in the ocean at a specific place and time. It’s a useful tool to help mariners steer clear of dangerous seas, but it may not be enough to protect them from a rogue wave that appears out of the blue.
Johannes Gemmrich, a research scientist at the University of Victoria in Canada who analyzed the 2020 rogue wave near Vancouver Island, says rogue waves are most often generated when waves travel at different speeds and occasionally overlap, supporting the linear addition model. But he believes wave asymmetry—when waves have higher peaks and lower troughs—plays a crucial role as well.
“If we allow for stronger asymmetry, the probability of extreme rogue waves increases drastically,” Gemmrich says.
A general formula for the sea
One school of mathematicians says it doesn’t matter what causes a rogue wave, because one can still predict rogue waves quite accurately using a statistical framework for rare occurrences called large deviation theory.
The idea behind this method is to model the most efficient way a rogue wave can form, then use that model to chart a particular rogue wave’s path of development. The theory can factor in linear and nonlinear effects depending on the scenario, which is why its proponents consider it a unifying theory—one that could perhaps be used to predict rogue waves in various ocean conditions.
“If you just look at the absolute most efficient way of forming these waves, it very nicely agrees with the actual observed ones,” says Tobias Grafke, a mathematician at the University of Warwick in the United Kingdom.
Grafke and a team of researchers tested this theory in wave channels, measured results against real-time wave observations, and found the method could predict rogue waves in both settings surprisingly well.
One problem with this framework, however, is that it’s extremely challenging to account for all the factors of a sea state at a specific point in time. If you’re the captain of a ship, the most helpful forecasting information would be derived from real-time observations, not statistical probabilities. Grafke says his team’s formula can account for the specifics of a given sea state, but the more variables you fold in, the harder it becomes to solve quickly.
“The more complex these [equations] are, the better the prediction, the higher the computation effort and time,” Chabchoub says. “It is therefore a trade-off between accuracy and time to obtain useful results.”
Real-time forecasting
Scientists have been moving toward real-time wave prediction technology, but the newer approaches need to be tested in real-life settings—a challenge given the rarity of rogue waves. In many cases, the computation process needs to be ramped up to match the speed of the waves.
Rogue waves can form in just “10 to 15 seconds in rough seas,” Fedele says. “It is still hard to make fast and accurate predictions in such a brief time interval.”
To predict a rogue wave, scientists would need a radar system to continuously measure waves near a boat, so they could run data through a mathematical model that paints a picture of the ocean’s surface at that moment. A model that calculates a new surface every five minutes would offer a relatively accurate prediction of how waves would evolve in the next several minutes.
Such a system is not a reality yet. “The technology is there. The question now is: How [do] you make it fast?” Fedele says.
As more rogue waves are measured, mathematicians may finally find a way to anticipate these deadly waves before they rise out of the ocean—a technology that Captain Dumont d’Urville could have only dreamed of back in 1826.
