Sea Kayaks: What They Are & Why You Need One for the Ocean

You have spent some time enjoying leisurely kayak trips and perhaps even taken on some rapids, and now you want to tackle the open seas. You’ve heard that your recreational kayak isn’t designed for oceans. But why is a sea kayak necessary?

A sea kayak is a specialized kayak designed to handle choppy ocean water. It is long and narrow, so it can ride the waves without capsizing. A skeg or rudder helps with steering. Safety features, such as bulkheads and perimeter lines, are needed should the kayak flip over.  

Sea kayaks are expensive, larger, and more challenging to move from your house to the beach. However, if you plan to kayak the ocean, you should not do so in a recreational kayak. Read on to learn how sea kayaks are different from other kayaks and why those design changes are necessary for a safe voyage.

A Brief Overview of What a Sea Kayak Is

A sea kayak, sometimes called a touring kayak, has numerous design features that make it ideal for kayaking open water. We will go over some of those features, and hopefully, you will know why you need a sea kayak and what features to look for as you shop for one.

The Purpose of a Sea Kayak

A sea kayak is designed for open seas. Many people’s first kayaking experience is in a recreational kayak on a river. Or you decided to be more adventurous and tried whitewater kayaking. For that, you probably rode in a river runner, creeker, or playboat. 

However, if you plan to kayak in the ocean or larger bodies of water, you need a sea kayak.   

The Defining Characteristics of a Sea Kayak

Recognizing a sea kayak is easy once you know what to look for. Some characteristics of a sea kayak include:

  • Long, Narrow Design – A sea kayak is thinner and longer than a recreational one.
  • Hatch Compartments – Although a recreational kayak might have a small hatch, sea kayaks often have two or three. Recreational kayaks often do not have bulkheads, an essential safety feature for sea kayaks.
  • Small Sitting Compartment – The choppy water requires a kayaker to have more control of their vessel. Experienced sea kayakers call this “wearing the boat.”
  • Additional Cords for Storage and Safety – Sea kayaks have safety cords along the perimeter as well as bungee cords for storing equipment.

How Sea Kayaks Compare to Other Types of Kayaks

Listed below are some other types of kayaks. Let’s see how sea kayaks compare to them.

  • Recreational kayaks are 10 to 12 foot boats used on rivers and lakes. Because they are very stable, recreational kayaks are excellent for beginners and taking leisurely trips down a river.
  • Whitewater kayaks are shorter than recreational kayaks. Features to help them navigate rough water include a curved bottom, planing or displacement hulls, and flat fronts for stability.  
  • Sit-on-Top kayaks are wide and have higher seats. These stable kayaks are ideal for beginners who have difficulty climbing into other kayaks, swimmers, and fishermen.
  • Additional kayak categories include inflatable, folding, fishing, pedaling, and kayak-canoe hybrids. Inflatable and folding kayaks are designed for travelers who have limited room. Fishing kayaks have additional space for fishing equipment and accessories and are often referred to as kayak-canoe hybrids.

Why Sea Kayaks are Recommended for Kayaking on the Ocean

If you plan to take a short trip on the ocean and can guarantee that there will be no wind, the weather will be mild, and the water will be calm, then a recreational kayak will do. However, should any of those things change, you will quickly realize why a recreational kayak is not intended to be used on the open seas.

Its Long, Narrow Design Is Built to Withstand Ocean Waves

A wider boat is more stable in smooth water because more of the boat’s surface area contacts the water. In smooth water, this has two advantages. First, when you tilt, the boat tilts less than a narrow boat. Also, getting into and out of a wide boat is easier.  

However, a wider boat also has a few disadvantages. The additional surface creates more friction, affecting the kayak’s speed. In addition, the extra surface area requires more effort from the kayaker. Luckily, river water is generally calmer than the ocean, and a kayaker relies on the river’s flow to help them.  

Ironically, the additional width is a disadvantage in the ocean. A thinner boat ignores most of the waves, while the wider boat tends to ride them. Also, the additional surface area that increases the effort required to paddle is intensified on the seas. Riding the waves will require extra effort already, so why make it even more difficult for yourself?

Finally, longer kayaks travel more quickly than shorter ones. This is due to the second wave pattern formed as the kayaker moves forward. Serious kayakers talk about the hull speed equation. This formula was developed by the naval engineer William Froude (source). Using his calculations—an 18-foot kayak has a hull speed 0.5 knots faster than a 14-foot boat (source).  

The Rudder or Skeg Keeps the Kayak on a Linear Course

Another feature common to most sea kayaks is the addition of either a rudder or a skeg. Both can help you paddle and navigate as you adjust to changing conditions, but they do so in different ways.

A skeg is a non-pivoting blade that sits in a slot in the kayak’s hull. In most kayaks, a slider on the cockpit side is used to drop and retract the blade. Although a skeg helps keep the kayak in a straight line, it is also used to trim or balance your kayak when water or wind conditions change. An experienced kayaker adjusts the skeg to adjust for crosswinds properly.

A kayak rudder is different from a skeg in several respects. The most visible one is that a rudder can be seen. Unlike a skeg that drops out of a slot on the kayak’s bottom, the rudder is attached to the stern. A second difference is that the kayaker can pivot the rudder from side to side.  

While the skeg is controlled with a slider, the rudder is turned and adjusted with foot pedals. Cables attached to the pedals control the rudder, allowing the kayaker to pivot the rudder. An additional cord system is used to lift it out of the water. Although a rudder is used to steer a boat, the rudder’s primary purpose is to keep the kayak traveling in a straight path.  

Debates about which is better are often settled for you by the kayak manufacturer. For example, a long sea kayak will often be outfitted with a rudder. 

Hatch Compartments Keep the Kayak Afloat When Swamped

Kayakers rely on the principle of buoyancy to stay afloat. When buying or renting a kayak, you don’t ask how much buoyancy can I buy? Instead, you ask about hatch compartments and bulkheads. Both of those help a kayak stay afloat, especially if the cockpit becomes flooded.  

So what is buoyancy, and how does it work?  

Buoyancy is the force that water and air exert against an object’s weight. As the kayak’s weight and its passenger press into the water, the pressure difference between the kayak’s bottom (more pressure) and the kayak’s top (less pressure) forces the kayak back up. The air that is stored in the kayak’s bulkhead and hatches helps keep the vessel afloat.

Compare it to what happens when you are floating in a pool and exhale. The air in your lungs helps you stay afloat, and without the air, you sink. The bulkhead and hatches serve the same purpose as the air in your lungs when it comes to helping you stay afloat.

Bulkheads are water-tight compartments that hold air—sort of like your lungs. The idea is that the amount of water that gets into a cockpit is not enough to sink the kayak. Kayaks can have a single bulkhead located behind the seat, but a sea kayak should have two bulkheads—one in the bow and another in the stern. The bulkheads keep the kayak afloat while also providing storage space.

The hatch gives you access to bulkheads, and they can be round or oval. The larger oval hatches let you fit in longer items. Besides the shape and size, there are additional considerations when choosing a hatch cover. The most important one is that the cover be airtight.

Hatches can be made from rubber or rigid plastic, depending on the type you are using.  

  • Rubber Hatch Covers – These fit over a rubber rim attached to the kayak. Finding replacements can be tricky since a hatch cover can be the same size as the rim, but the rim’s lip might not match the cover.
  • Deck Plates – These hatch covers are made from hard plastic and work like jar lids. They usually have some type of twist lock.

Some hatch covers have a bungee cord or hatch strap system to provide additional security.    

Sea kayaks often have a third hatch, usually behind the cockpit. The smaller day hatch provides a storage area that the kayaker can access while in the water. 

Things you want in your day hatch might include:

  • sunscreen and sunglasses
  • way to get someone warm
  • source of communication
  • first aid kit
  • repair kit
  • snacks and water
  • aerial flares

Your day hatch ideally has a place for everything and everything in its place. When you reach for something, you don’t want to be rooting through it to find what you need. Preparation is essential for safe ocean kayaking.

For a more in-depth and visual explanation of buoyancy, check out this video:

Perimeter Lines Offer Swamped Paddlers Something to Latch Onto

Sometimes it’s impossible to grab onto the cockpit rim—the kayak is too slippery, hands are numb, the cockpit can’t be reached. So sea kayaks have perimeter lines so a person can quickly grab onto a kayak if it has capsized or if another kayaker is coming to rescue a swimmer. 

Perimeter lines, sometimes called deck lines, are non-stretchy (also known as static) cords that people can use in one of two ways:

  • A swimmer in the water can use it to hold onto the kayak.
  • Someone in another boat or onshore can pull the kayak.

Perimeter lines should be loose enough that a person can slide their fingers underneath them but not so loose that gear gets snagged in them. The lines are attached by deck loops or through recesses. Some kayaks have a single rope that circles the boat, while other kayaks have two sections—one on the fore and the other on the aft.  

To provide visibility, manufacturers will often use a cord with reflective material woven into it. The SGT Knots Polypropylene rope is an example of a marine cord that is reflective, rot, and moisture resistant. Check perimeter lines and replace them if they are frayed or damaged. Your repair kit should include some static cordage.

Lower Seat Back Grants Paddlers Extra Mobility

Kayaking in choppy waters requires more mobility than kayaking on a river. Having a lower seatback means that it is easier to perform maneuvers when on the water. Leaning back to do rolls is also easier. 

Narrower Cockpit Offers Greater Lower Body Control Over Kayak

A kayak’s movement is affected by water’s hydrodynamic forces, also known as lift and drag. Ocean kayaking requires that you deal with waves. 

The size and type of waves a kayaker encounters are affected by:

  • wind speed
  • fetch (the amount of open water)
  • how long the wind blows

These conditions determine whether the waves will be ripples, seas, or swells.  

  • Ripples – the small waves
  • Seas – larger waves whose movements are not regular
  • Swells – stable, predictable waves

Because ocean water conditions are much less predictable, the more you can “wear the boat,” the better you will navigate. A narrow cockpit means that you will have more points of contact. Foot braces, thigh or knee braces, and adjustable seats provide contact points. A narrow cockpit adds additional contact points as you lean into one side or the other.

Better Equipped to Store Gear for Longer Trips on the Water

We have already covered that sea kayaks have bulkheads with oval hatches so that you can store additional gear in them. Kayaks also use bungee cords for storage. These cords come in several patterns, with the most common pattern being an X or XX pattern. The cords behind the cockpit are often used to hold a paddle.  

Since you should not assume that what you put under the bungee cord will stay, you should use clips or carabiners to attach objects you don’t want to lose. Should your kayak flip over, there is no guarantee that the bungee cords will hold your stuff. 

This Marine Masters Expanded Deck Rigging Kit would be an excellent way to add or repair rigging. However, the marine-grade cord means you would not use it for a perimeter line.

Equipment You Want to Take on a Sea Kayak

The dangers of ocean kayaking require that you take along a lot of equipment and supplies. Although this isn’t a complete list, it gives you some ideas of why you need more storage space.

  • Spray Skirt – From breaking waves to the weight of additional equipment, the chances of getting water into your cockpit are far greater on the ocean. A spray skirt keeps out much of that cold water. Even if you capsize, the skirt can keep water from flooding the cockpit.
  • Lights – You should have lights and flares at a minimum. A waterproof headlamp or lights that can be mounted to the deck will help rescuers see your kayak.
  • Water & Food – Bring along more than you think you will need in case you are out longer than you think you should be.  
  • Clothing – Whatever clothes you are wearing at launch, have additional layers if you need to adjust to changing weather.  
  • Navigation & Communication – Cell phone reception is poor or not at all the further you get from shore. An emergency whistle, compass, ocean chart, high-frequency radio, or personal locator beacon are essential.
  • First Aid – You should take along two first aid kits—one for people and the other for your boat.  

Bottom Line—Will Any Type of Kayak Work on the Ocean?

Kayaking is a fun sport, but you cannot use a recreational kayak on the ocean. The sea kayak design—with its long and narrow shape, closed bulkheads, skeg or rudder, narrow cockpit, and perimeter lines—help the kayak navigate the choppy seas. A recreational kayak is more likely to tip in the ocean and fill with water.

Like you can’t use any kayak on the ocean, not every kayaker should be taking to the open seas. Ocean kayaking is more strenuous. In recreational kayaking, the shore is often not far away. The same cannot be said for the ocean. Before you attempt sea kayaking, you should take lessons, have experience kayaking, and go with a group.

Sources: 1 2

Austin Carmody

I am the owner of HydroPursuit. I enjoy kicking back and getting out on the water as much as I can in my free time.

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