I think the TI is a little drier in the seat area because the bottom of the seats are usually above the waterline, so they do drain eventually but I also got tired of sitting in water most of the time. My thought is I don't really want to spend a great deal of money on new seats, some of those suckers are over $200 bucks (ouch). Actually I'm pretty comfortable in the standard Hobie seat as long as it is upright, but at least on mine the seat straps slip all the time and it drives me nuts. I very seldom need to adjust my seat so I ended up just tying a piece of paracord so it can only slip back so far then the paracord pulls tight, this actually works ok.
I'm not sure there is a way to keep the inside of the seat area dry because of splashing and water entering from just about anyplace it desires.
What I ended up doing is just elevating myself up about 1 1/2 inches in the seat, and the problem is solved. How you do it doesn't really matter. I have heard that the I-comfort pad from Hobie works well. I'm a firm believer in keeping things simple and inexpensive.
What I came up with was I cut up an old pool mattress, though any type of foam or seat cushion should work (something that will hold up in water of course). The whole trick to it is how do you attach it to the seat easily and reliably. What I used is just a common laundry bag (actually mine is a Lobster catch bag that I picked up at the Scuba shop (most fishing supply also sell catch bags). Basically I just cut the seat cushion so it roughly resembles the shape of the seat bottom, then slid the foam and the seat bottom into the laundry bag and just cinched it shut at the back. I did it a couple yrs ago now and it's been in the boat ever since with no issues of any kind. I am in my TI for many hours most weekends and before adding the padding I would get uncomfortable quickly from the hard standard seat bottom, this little extra padding makes all the difference in the world, and best yet if keeps my butt above the water level in the seat area so my bum stays dry.
Here is a pic of the old pool mattress after I cut it roughly to shape, and the Lobster (Laundry/catch) bag. An added benefit is the bag is a little taller than the seat so I fold it inside out on the bottom and store all my charts in there.
Raising the seat only 1 1/2 inches worked out quite nice, my center of gravity is still very low in the boat, and I don't hit my head on the sail at all.
If you search for Kayak/canoe cushion you will find hundreds to choose from if you don't want to make one.http://www.amazon.com/s/?ie=UTF8&keywor ... gynxn14_pp
The whole trick is they are inexpensive (usually under $30 bucks), and super easy to install, just zip them into the laundry bag along with the seat bottom, and you never have to fuss with it again. Just that little extra height makes all the difference in the world. I don't worry about drainage, the water finds it own way out thru the mesh of the bag.
Hope this helps
Hope this helps