Types Of Kayak Hulls—And Why They Matter

Paddling Buyer’s Guide

A kayak’s performance is ultimately determined by the shape of its bottom and how these curves (or “lines,” in nautical terms) interact with the water to influence characteristics like glide, stability and maneuverability. This article describes why kayak hull types are integral to performance and investigates the attributes of different kayak hull shapes you’ll find on recreational and touring kayaks.

What is the hull of a kayak?

The bottom of a kayak is called the hull. This “floating surface” forms an interface between the kayak and the water, and thus plays a primary role in determining how the boat will perform. Ultimately, the design of the hull of a kayak is the main factor in whether or not a kayak is right for you.

An educated buyer can look at a kayak hull design and estimate how the boat will perform in the water. Different kayak hull shapes will have different paddling characteristics; speed and glide, tracking and maneuverability, and stability are all directly influenced by kayak hull shapes.

In general, kayak hull design boils down to two things: First, rocker, or upsweep of the kayak’s hull from bow to stern, establishes the balance between tracking and maneuverability. For example, whitewater kayaks feature plenty of rocker to assist agile handling in rapids, while sea kayaks have minimal rocker to enable easier straight-line travel (A.K.A. tracking).

Second, the cross-section of the hull (as if a slice were taken from the kayak from side to side) determines stability. The way various kayak hull types influence stability is discussed at length in the next section of this article.

Kayak hull types

Pontoon hull kayak

This type of hull is often also called a “double hull kayak,” “tunnel hull,” “dual hull design” or “catamaran hull kayak.” This kayak hull type prioritizes stability, at the expense of speed and maneuverability. Like a pontoon boat, a pontoon hull kayak is designed to sit flat on the water and resist rocking from side to side. It’s a common kayak hull design for beginner sit-on-top kayaks. The large surface area of this kayak hull type makes it slower to accelerate and requires more effort to maintain a cruising pace.

Pontoon hull kayaks track well; that is, they tend to move straight through the water and are more difficult to turn. Choose a pontoon hull kayak if you’re a beginner paddler looking for the ultimate in stability. However, be aware that this type of kayak hull design will also limit your ability to perform more advanced paddling techniques, such as edging the kayak (which increases maneuverability in single-hull kayaks).

Tri hull kayak

This type of hull is often also called a “cathedral hull kayak,” “kayak dihedral hull design,” or “multi-channel hull kayak.” This kayak hull design is commonly used in sit-on-top kayaks (especially those manufactured by Ocean Kayaks). A tri-hull kayak provides the reassuring stability of a catamaran hull with the enhanced tracking of a well-defined keel line—that is, a V-like structure running along the bottom of the kayak from bow to stern.

Manufacturers of tri hull kayak designs can also achieve more maneuverability than pontoon kayaks by adding rocker (curvature) to the outer hulls, which allows the kayak to turn more easily yet still feel supremely stable. Look for a tri hull design if you want a higher performance beginner sit-on-top kayak.

Displacement hull kayak

All recreational, touring and sea kayaks feature what’s known as a “displacement hull.” This means the kayak pushes (or displaces) water as it moves (in contrast, a “planing hull,” often identifiable by a flat bottom, will plane or skip across the water with minimal resistance—once it reaches a certain speed. Think surfboards and surf-inspired standup paddleboards).

Flat hull kayak

A flat hull kayak is defined by great stability. That’s because the paddler is effectively floating atop a larger, flat surface that resists rolling from side to side in the water. Flat hull kayaks are great for beginners, and commonly used in recreational and touring kayaks. This kayak hull design is often paired with a wider-than-average width, to further enhance stability and support larger paddlers. Flat hull kayaks feel most stable on flat water, a phenomenon known as “primary stability.”

However, they can feel tippy and less reassuring to the paddler when waves or current rock the kayak from side to side. In these circumstances, flat hull kayaks are said to have poor “secondary stability,” and are more prone to capsizing than kayaks with rounded hulls. Flat hull kayaks also tend to be slower because their boxy shape moves through the water with greater resistance than rounder hull designs.

Whitewater playboats (or freestyle kayaks)—small, sub-seven-foot-long kayaks meant for surfing on stationary river waves—also feature flat-bottom, planing hulls, which allow an advanced paddler to “skip” on the surface of the water to perform acrobatic maneuvers.

Round hull kayak

In contrast to a flat bottom, a round hull kayak has greater secondary stability (more resistant to capsize in waves, chop and current). However, a round hull has far less primary stability (that is, it feels tippier when sitting flat on the water); therefore, this kayak hull design is less suitable for beginners. More advanced touring and sea kayaks tend to have rounder hulls, which makes them faster in the water than flat-bottom kayaks.

Planing hull kayak

Planing hulls are found exclusively in whitewater freestyle kayaks. These small, sub-seven-foot-long kayaks are meant for surfing on stationary river waves. Planing hulls are flat, like a surfboard. This allows an advanced paddler to “skip” on the surface of the water to perform acrobatic maneuvers.

Planing hulls feel stable on the water. However, their larger surface area makes them slower and feel more cumbersome for downriver paddling.

V hull kayak

A V-hull kayak features a pronounced keel line (that is, a shallow V-shaped ridge running from bow to stern along the bottom of the kayak). This allows the kayak to hold its course (or track) better than a flat bottom kayak, since the V-shape of the keel line resists turning more than a flatter hull. The flipside to solid tracking, however, is reduced maneuverability.

More advanced paddlers overcome this tendency by performing turning strokes with the kayak tilted (also known as edging the kayak) to lift the V-shaped keel out of the water. V-shape kayaks feel less stable when sitting flat on the water, with a tendency to rock from side to side. However, this translates to greater stability in waves and current—another desirable attribute for more advanced paddlers.

Comparing different hull types

  • Flat bottom vs V-hull kayak

    There are two main differences between flat bottom and V-hull kayaks: tracking and stability. A V-hull kayak will tend to hold its course (or track) better than a flat bottom kayak, since the V-shape of the keel line resists turning more than a flatter hull. Meanwhile, a flat-bottom kayak will feel more stable on the water than a V-bottom, which has a tendency to rock from side to side on flat water.

    However, the stability characteristics of flat bottom and V-hull kayaks are opposite in waves, chop or current: in these conditions, a V-hull kayak will feel more stable and resistant to capsize than a kayak with a flat bottom. In general, V-hull kayaks are more efficient to paddle, with better speed and glide than flat bottom kayaks. V-hulls are typically associated with more advanced kayak designs while flat bottom kayaks are more suitable for beginners and flatwater conditions.

  • Planing hull vs displacement hull

    The question of planing hull vs displacement hull pertains exclusively to whitewater kayaks. (Recreational, touring and sea kayaks always use displacement hull designs.) A planing hull whitewater kayak (or “freestyle kayak”) is meant for surfing stationary waves. Its flat surface feels stable and, for advanced whitewater boaters, allows the kayak to skip (or bounce) on the wave to enable aerial freestyle moves.

    However, a planing hull is slower, less responsive and more cumbersome to paddle downriver. In contrast, displacement hulls are typically used on river running kayaks and creek boats. This kayak hull shape is more predictable, faster, versatile and easier to paddle—but less suitable for performing freestyle maneuvers.

Hulls by kayak type

Recreational kayak hull design

Recreational kayaks are made for beginners and stability is the primary objective of recreational kayak hull design. In this category of kayak you’ll find flat bottom hulls for maximum stability and comfort in flat water conditions. Some manufacturers further enhance stability with pontoon or catamaran kayak hull designs. Sit-on-top kayaks often feature tri-hull (also known as “cathedral hull kayak,” “kayak dihedral hull design” or “multi-channel hull kayak”) designs that are both stable and extremely easy to paddle in a straight line.

The large surface area of recreational kayak hull designs make these types of kayaks feel slow and sluggish on the water. The greatest drawback of most recreational kayak hull design is poor secondary stability; that is, the kayak will feel tippier and offer less forgiving performance in waves, chop and current.

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Sea kayak hull design

Sea kayaks are meant for more advanced paddlers than recreational kayaks, so you can expect that sea kayak hull designs are meant for greater performance. You will find some flat bottom sea kayaks (generally boats meant for larger paddlers), but the majority have rounded or v-shape bottoms for better efficiency and maneuverability—and enhanced stability in rough water (a feature known as “secondary stability”).

Novice paddlers who are more familiar with recreational kayaks will immediately notice the “tippiness” of a sea kayak. However, this feeling is quickly replaced by sensations of speed and glide as the paddler develops their skills and becomes more comfortable in the boat.

Sea kayaks are longer than recreational kayaks and with greater length comes more glide and speed. These characteristics are enhanced in kayaks with straight keel lines (that is, kayaks with little upsweep in the hull from bow to stern, A.K.A. “rocker”).

Some high-performance kayaks, including those manufactured by Epic and Stellar, feature plumb (near-vertical) bow and sterns which further lengthen the keel line and contribute to greater speed and efficiency. The tradeoff to a long keel line is less maneuverability; shorter kayaks, and those with more rocker, or upsweep to the keel line at the bow and stern, tend to be easier to turn.

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Racing kayak hull design

As a rule, racing kayaks feature displacement hulls with long, straight keel lines. The bow and stern of racing kayak hulls are plumb (nearly vertical) to lengthen the waterline. A longer waterline equates to more speed and straighter tracking, both of which are definite attributes in a racing or fitness kayak.

However, these characteristics severely hinder maneuverability. As a result, most fitness kayaks feature rudders for easier handling and turning. Racing kayak hulls have round cross-sections to minimize surface area for less resistance and optimal glide.

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Inflatable kayak hull

Inflatable kayak hull designs face the significant challenge of creating a stiff, air-filled hull that slices (rather than flexes) through the water as efficiently as possible. As a result, inflatables concentrate air in narrow tubes along the bottom of the kayak to create a stiff hull that supports the paddler’s weight and doesn’t feel noodley in the water.

However, even the best inflatable kayak will never be as efficient to paddle as a hard-shell kayak. The flat cross-sectional profile of an inflatable kayak hull is extremely stable—but its relatively large surface area further eats into the kayak’s glide.

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Sit-on-top kayak hull design

Sit-on-top kayaks are designed to be stable, a characteristic that’s built into sit-on-top kayak hull design. Basic sit-on-top kayaks achieve stability with a flat bottom. This hull design offers great stability but has unremarkable paddling performance in terms of glide and maneuverability. Some sit-on-top kayaks use pontoon or catamaran hull design, essentially creating two round hulls on either side of the kayak, to maximize stability with a slight reduction in drag.

The best sit-on-top kayaks use a cathedral hull design, which capitalizes on the stability of a catamaran but adds a center v-shaped keel line running from bow to stern for better tracking, as well as rockered side panels for maneuverability. Expect to find these hull designs in Ocean Kayak sit-on-top kayaks.

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Whitewater kayak hull design

Whitewater kayak hull design is divided into two categories: Displacement hulls, which feature round or arched bottoms for a blend of paddling performance (maneuverability, glide, ease of handling) and stability; and planing hulls with flat bottoms and some upturn at the bow and stern and hard, boxy edges (where the sides of the kayak meet the bottom).

Displacement hulls are predictable for use in river running and creekboating situations, while planing hulls can skim, skip and bounce on a stationary wave to enable acrobatic freestyle kayak maneuvers.

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Hulls by brand

Bonafide kayak hull design

Bonafide kayak hull design aims for maximum stability. That makes sense, given Bonafide’s reputation as a fishing kayak manufacturer. Bonafide calls its hull design a “hybrid catamaran” with pronounced pontoon tubes on either side of the hull for a secure feeling whether you’re sitting or standing on the boat. The manufacturer attempts to gain some maneuverability with curved chines, or edges, in the sidewalls of the kayak.

More skilled paddlers can engage the chines by shifting their weight to make the kayak turn more easily, with the same comfortable stability as when the kayak is resting flat on the water. A subtle keel in the stern of the kayak improves tracking.

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Ocean Kayak hull design

Ocean Kayak is the original sit-on-top kayak manufacturer and its hull designs reflect an intimate knowledge of how a kayak hull interacts with a variety of water conditions. Most Ocean Kayak hull designs, including the popular Malibu lineup, rely on a cathedral hull for a blend of stability, tracking and maneuverability.

Ocean Kayak achieves stability with defined pontoons on either side of the keel line. Meanwhile, a V-like structure running between the pontoons and along the bottom of the kayak from bow to stern improves tracking. Finally, curved side walls allow the kayak to turn more easily without compromising stability.

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Pelican kayak hull design

Pelican kayak hull design is divided into two categories. Pelican’s recreational and fishing kayaks utilize a twin-arched multichine hull, which is essentially a pontoon hull (for maximum stability) with multiple chines (or edges) on the side of the hull to improve maneuverability and make these beginner-friendly designs easy to handle.

Meanwhile, Pelican’s Sprint lineup of day touring kayaks are meant for more responsive performance, featuring a deep V-hull and well-defined hard chines, combining the solid tracking and increased speed of a V-hull with flat bottom panels for reassuring stability.

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Kayak hull speed

It’s generally easy to estimate hull speed in a kayak. Hull speed comes down to a few variables: first, the length of the hull (specifically, the length of the waterline from bow to stern); second, the cross-section of the hull and what this means for the contact surface area between the boat and the water; and third, the amount of rocker in the kayak’s keel line.

All things considered equal, the longer the kayak, the greater the hull speed. However, it’s important to note that longer kayaks also have more surface area—and therefore more friction and resistance—than smaller kayaks, so maximum hull speed is also a function of the strength and efficiency of the paddler. Resistance can be minimized in kayak hull design by reducing surface area with a round profile, but at the expense of stability.

A kayak with minimal rocker, or upsweep from bow to stern, will have a longer waterline length and therefore be faster and straighter tracking—but with reduced maneuverability.

What is the best hull shape for a kayak?

The best hull shape for a kayak is based entirely on the paddler, including how and where you’ll paddle, your body size, comfort in the boat and aspirations in kayaking. Every design feature has a tradeoff. For example, the flat bottom and pontoon hulls of recreational kayaks achieve maximum stability, at the expense of paddling performance.

Additionally, a flat bottom kayak actually becomes less stable and secure in waves and current. High-performance sea kayaks usually feature round or v-shaped hulls for greater speed, but these kayaks often feel tippy in flat water conditions (though their hull designs maximize secondary stability, making them more resistant to capsize in rough water).

The key to finding the best kayak hull shape for you is trying as many boats as possible before committing to a purchase. Getting to know the balances between rocker and tracking and primary and secondary stability will help you decide what’s best for you.

Fast kayak hull design

The fastest hull designs have a straight keel line with minimal rocker (upsweep from bow to stern) and a round bottom (cross-sectional profile). These hull design features achieve two things: first, minimal rocker maximizes the waterline length (vertical, also known as “plumb,” bow and stern profiles add additional length to the waterline), which makes for greater maximum hull speed.

Second, a round bottom minimizes water resistance on the hull, making it glide easier through the water. The trade-off to these kayak hull design characteristics are reduced maneuverability and stability. Examples of dedicated fast kayak hull designs are the fitness, racing and surf ski-inspired kayaks produced by Epic and Stellar Kayaks.

Most stable kayak hull design

The most stable kayak hull design incorporates a flat bottom. This creates a flat, stable platform for the paddler to float atop the water. Modified flat bottom designs include pontoon kayak hulls (which impart greater rigidity to inflatable kayaks) and cathedral (or tri-hull) designs, which combine the stability of a flat-bottom kayak with a finer blend of tracking and maneuverability.

Flat bottom kayaks are most stable on flat water. They become less predictable and less stable in waves, chop and current. In these conditions, v-hull and round hull kayak designs (which are otherwise less stable in flatwater conditions) feel more secure and resistant to capsizing.

When it comes to kayak hull design, the simple answer is, there are no simple answers. Use this guide to kayak hull types to understand how different kayak hull designs affect performance, and then consider what attributes are most important to you.

Most importantly, try to test paddle as many different kayak types as you can before making a decision. Researching kayak hull types online is a great start, but sitting in a kayak on the water is the best way to know if it’s right for you.

 

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