Both hardshell and inflatable kayaks can be categorized into two different styles:
The two designs differ drastically from one another, and each suits a different purpose.
The differences between sit-on-top vs. sit-in kayaks
The most apparent distinction between sit-inside and sit-on-top inflatable kayaks (& hardshell models) is that SIKs have an enclosed cockpit that positions the paddler inside the boat at or below the water level. In contrast, SOT kayakers sit on top of the kayak above the water’s surface.
This fundamental divergence of design affects every aspect of their use and purpose.
The sit-on-top model is the most popular design among beginners and recreational kayakers because it does not make the paddler feel like they are trapped inside of the kayak’s cockpit if they capsize.
If they do tip over for some reason, they are far easier to reen
The sit-inside model is more prevalent among intermediate and advanced paddlers because its design provides a significantly lower center of gravity, resulting in enhanced secondary stability during specific activities (which I’ll talk about later).
The cockpit of a SIK kayak is surrounded by a rim for attaching a spray skirt to keep water out.
They have similarities as well
Even though there are some significant differences between the two styles, their main parts are similar:
Both types of kayaks have:
A seat (or seats in case of tandem kayaks).
Foot support like simple footwells or adjustable foot pedals (which are more comfortable on a full day of paddling).
Top of the line kayaks will additionally have a built-in backrest to make paddling for hours more comfortable.
The pros and cons of sit-inside & sit-on-top kayaks
Sit-Inside kayak pros
The most significant advantage of a sit-inside kayak is that its center of gravity is lower than that of a sit-on-top kayak, which provides better secondary stability. This enables you to lean the boat on its side edge for more efficient turning and stay upright in rough seas. There is a trade-off, though, which I’ll get to in the cons section.
Because sit-inside kayaks have a lower center of gravity, they can be made much narrower than a sit-on-top model. Being slimmer and longer means they are faster and easier to paddle than SOT kayaks, making them well suited for longer trips.
The lower profile also means that sit-inside kayaks are affected by wind to a lesser extent.
The enclosed cockpit provides protection from the sun or rough water.
A spray skirt can easily be attached to the cockpit coaming for full protection from rain, snow, or frigid water during winter paddling. A well-sealed high-quality spray skirt can also be a safety feature because it will keep water out of the cockpit in case you flip (providing you can roll back and correct your white water kayak).
Sitting inside a cockpit lets you place your legs against the side of the kayak & the underside of the deck. Your body effectively becomes one with the kayak’s body to enhance your control of the kayak, making it more maneuverable.
You will find there’s room inside the kayak to store your equipment and keep them dry. Water can’t get in through self-draining scupper holes found on SOK kayaks. Some sit-in kayaks even have integrated watertight storage compartments.
Due to the narrower beam of SIK kayaks, you can use a shorter paddle. This makes the boat easier to propel forward because the moment arm will be tighter. (The moment arm is the distance from your centerline to the part of the paddle entering the water. The shorter it is, the easier it is to paddle.)