Anatomy of a Kayak


By Todd Terrill

[dropcap]W[/dropcap]hat’s on the inside of a kayak besides a paddler? I will try to describe how kayaks are made and what is different about each method. None of the manufacturing methods are bad, just some are better than others. What are kayaks made of? Kayaks can be composed of several materials, each having their own benefits and detriments. Plastic is the most common material used in kayaks today; however all plastics are not created equal. Some less expensive plastics are brittle and do not weather well, but are used to manufacture less expensive kayaks. A method some kayak manufacturers use is to make the plastic thinner to save cost at the expense of the uninformed consumer. There are handmade kayaks made from a variety of woods and can be very ornate. Wooden kayaks are easily scratched or damaged. Kayak building kits are available offering the buyer the challenge of building his own kayak with custom design options. These kayaks are typically very sleek and are often designed to be used for touring.

Better made kayaks are made from polyethylene, developed to have UV protection and color incorporated into the process to resist fade. A thicker wall material means a slightly heavier vessel yet it is much more durable. The thickness of a kayak can usually be determined by tapping on the sidewall, and the deeper the resonation, the heavier the material. Most kayak dealers will be happy to show you a sample of the material your potential kayak purchase is made of. I have found that “big box” retailers may not have sales staff familiar with the manufacture of kayaks they off er for sale. I recommend that you shop around and be informed through research prior to making a purchase.

Kevlar is a very strong material used in the manufacture of some kayaks along with carbon fiber and fiberglass. These are very lightweight, fast and durable. Most racing kayaks and white water kayaks are made with these materials due to the durability. They have a narrow hull, a sleek design, and allow enough room for the kayaker in the cockpit, but little or no storage.

The hull design of a kayak tells you how well it will cut through the water, called tracking, and how stable it will be in the water. At the front or bow of the kayak, the keel is angled. Th e deeper the vee of the bow keel, the better tracking it will have. At the back or stern, the keel determines how maneuverable the kayak will be. The larger the keel, the more resistance it will have when turning. This is why many kayaks have an optional rudder attached to aid in steering. The bottom of the kayak determines it’s stability in the water. The wider and flatter the bottom, the more stability it will offer. Tunnel grooves in the kayak bottom allow water to flow underneath without taking away from stability. Some kayaks have a pontoon style bottom adding to stability.

Plastic kayaks are made using one of two methods: Thermoforming—a process of heating the raw plastic using pressure to force the melted plastic into a hot mold form. This is the same process seen at theme parks to make small plastic characters in a machine. The mold then cools and the plastic cast is removed. Excess plastic is trimmed away and then cut outs are made for the various access holes, hatches and cockpit for sit inside models.

Roto-molding is a process of filling a two part mold with plastic beading. The mold is rotated during the process to ensure even distribution of the plastic beading. The mold is cooled and the kayak is removed. The seam lines are trimmed and the access holes and hatches are cut out. This process allows for a more even and thicker wall to be produced.

I almost forgot one of my favorite kayak styles, the inflatable. This type of kayak is made of vinyl or canvas material, and some have a semi-rigid frame that is assembled at the time of use. They are inflated using either a foot operated pump or a small electric air compressor. Good points to consider for them are that they are easy to transport and store. The drawbacks are that they tend not to be sharp object friendly (oyster shells and barnacles), and they are not as durable as a solid constructed kayak.

I have had the opportunity to own and paddle several styles and makes of kayaks over the years—everything from the least expensive to the pricey ones. In that time I have experienced a fair share of unfortunate moments, like running too shallow, scraping mangrove roots, bumping into barnacle encrusted dock posts, and of course winding up sitting perched atop an oyster bed in my kayak. I have learned that it is these moments when you appreciate that the kayak you are sitting in is made of durable material and well manufactured. I realize this is fairly dry information. But, hopefully it will help keep you dry while enjoying the sport of kayaking. Stay well and paddle straight!