Bulkheads can make a kayak less likely to flood, but can also make it harder to right a flooded kayak.
There are two different types of kayak cockpits, so you should decide which one you want before you buy a kayak. These are integrated cockpits and those that have bulkheads. The major difference is that while an integrated kayak cockpit is just an open space inside the kayak for you to sit in, the bulkhead kayak will be split into the place where you sit, and then a few air-tight, water-tight compartments.
There are a lot of discussions as to which type of kayak is safer. Some people will argue that bulkheads are safer while others say that the integrated kayak is best. In a lot of cases, however, you should probably go with the kayak that does not have bulkheads.
One reason for this is that a lot of studies have been done on kayaks which have bulkheads in order to find out how safe they really are. While it is a lot harder to sink a bulkhead kayak, once it is filled with water, it is considerably harder to right. In some cases, it may even be impossible. Due to the nature of the bulkheads, it will also be harder to get the water out after they flood. This is in comparison to an integrated cockpit, where all of the water is relatively easy to pump out should any get into the kayak.
While you can always hope that the bulkheads never get filled with water and likely be fine, there is still that slight chance. If you are just starting kayaking, then you will probably want to use a kayak that is integrated instead of split up into bulkheads.
The reason for this is that if you make it harder for you to right your kayak when you already do not have all that much experience doing so, you may find yourself at see with a capsized kayak and unable to get back in and paddle to shore.
However, no matter which type of kayak you use, you should make sure that you have all of the right equipment. Just make sure that you are aware that your kayak with bulkheads will be a little bit harder to right if it tips over than a kayak with a regular, integrated cockpit.