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.
Sit-Inside Kayak Cons
The single biggest con against sit-inside kayaks concerns floatation and ease of rescue, as the cockpit can take in a lot of water in case you capsize.
Touring kayaks have 1 or 2 integrated bulkheads to circumvent this. But “what is a bulkhead”, you ask?
A kayak bulkhead is a built-in compartment, which traps air inside of the kayak. The bulkhead limits how much water can get into the boat and acts as a floatation chamber to keep it afloat if you swamp. Additionally, bulkheads have a hatch so that you can use them to dry-store supplies as well.
Most recreational SIT kayaks will not have a bulkhead, but the better ones have a single one behind the seat.
If you are alone, flipping a swamped kayak back is very difficult, and so is getting the water out of it. Paddling a kayak filled with water is close to impossible unless it has bulkheads that stayed dry. For this reason, beginners using a SIK kayaks should paddle close to shore, so they can swim out and empty their kayak if they capsize.
If you plan on going out on open water, you need a touring kayak with bulkheads, and first, learn how to correct your capsized kayak and get back into it. Coastal paddling is a treat, but you have to prepare to stay safe.
You can only carry items that fit through the cockpit and other hatches. Tieing larger items on deck degrades performance and your balance.
Remember the increased secondary stability of SIK kayaks due to their lower center of gravity? Well, here is the flip side. The low sitting position causes them to have less primary stability.