Alexis,

In your title you indicated it was an SOF. As I read your post it sounds like it's not an SOF. Most skin on frames don't have a seat but do have a thin pad to sit on. They rely on the brace behind the cockpit to keep your butt in place. If your talking about any other boat you need to be more specific on what type, the beam width, foot bracing, how well the boat fits you, etc... Some boats fit some people just fine without a seat some don't. A lot of it is personal preference as well. If you fit in the boat fairly sloppy you will most likely want a seat. A seat also helps insulate your butt.