Folding boats are made of fabric that stretches over a frame and have the advantage of being easily disassembled for storage. If you like flying to exotic places, they are as easy to transport as a piece of luggage. With all these things to think about, you may want to rent a boat for a day. And if at all possible, buy the best you can afford in plastic, fiberglass, or fabric. Your boat must have some internal flotation or it will sink below the surface after you capsize.
Some manufacturers create a wall, or bulkhead that separates the space inside the kayak.
A typical arrangement has one bulkhead behind the seat and one beyond your feet. These compartments create air pockets that can be used to store gear and can be accessed by the hatches on top of the boat. Some manufacturers make these areas watertight with waterproof hatch covers and sealed bulkheads, but this is not always the case. If your compartments are not waterproof, you'll have to put everything you carry in dry bags. If your boat has no bulkheads, you can use air bags, which, when inflated, will keep most of the water out after a capsize.