there are 3 styles of seat pegs. all pictured here in Hobie's catalog.
The oldest style 81265001 is peg that may expand a little from the screw in it, but is one piece. The 2008 boat I bought had very weathered seat because these plugs were never removed to remove the seat, and it got too much sun. Once i did remove them, they did not stay in all that well.
The next style 81265101 was the one Chekika has, which a diagonal split in them. They were an improvement, but I sometimes had problems getting these tight enough, and it worried me to try, for fear of splitting the plastic of the seat hole.
The newest style (multiple parts) has a threaded hole in the plastic of the boat, into which a receiver screws, Then the twist pegs insert into the receiver, and are twisted like a key to lock them in. They are quite secure, but make it easy to take the seat in and out (unless they jam up with sand or something, which some owners have reported).
I adapted both my boats (an '08 with V1 pegs, a '10 with V2 pegs) to the V3 pegs, and really like them,
Hobie sells but apparently does not advertise a kit for the conversion (part 81276203). In addition a pair of the twist loc pins for the seat and a pair of receivers, it has a PVC slip plug fitting (3/4") which they recommend gluing onto the nipple of the seat peg hole inside the boat with included fast-set epoxy before tapping threads into the peg hole from outside (to prevent splitting the plastic with the tap, I expect). I did not put on the pvc's, and tapped the hole with a modified 3/4" bolt as shown in this post by Stringy. http://www.hobiecat.com/forums/viewtopic.php?f=69&t=40645&hilit=SEAT+PEGS&start=15#p187100
. Doing this, to minimize splitting pressure, I reversed, screwed completely out, and cleared shavings very often, and have had no splitting issues. (It might be easier with a real tap, but aside from the cost the taps I could get do not have bottoms as square as the home made bolt one, thus increased danger of the receiver splitting the hole as you thread it into the bottom of the tapering hole they leave). I did not glue them in, they show no sign of coming out in normal use, and if the pins do jam I would like them to be able to screw out under more pressure. I also ordered extra receivers (81275001)for the second set of holes, even though I only use one set of holes, just so the boats would be more like the newer stock.
I am very happy with the new seat pegs.