For those of us with pre-2015 islands, here is a simple seat mod that a) keeps you a bit drier, b) gives you a cushier ride, c) permits easy haka use and d) requires no permanent alterations to the boat. I have been using this mod for a couple of season and it works well.
First, you will need what I call the "false floor". This is simply a mat with channels that will allow water passage underneath. I used a 12" x 16" silicone drying mat, which is a little pricey, but a ribbed floor runner or a door mat with rubber spikes will work well. The important thing is that is soft, not slide around alot, and the ribs will not crush under weight. Here is the mat "rib side up". You want the ribs to run bow to stern.
Now flip the mat over "rib side down".
Next, I add a foam gardening cushion that has been notched around the seat pegs.
Now, the Hobie seat. You can see, this mod raises you up about 1", while providing a pathway for the water to drain. The Hobie seat, when using the back peg holes, normally blocks the drains to an extent. This mod avoids that issue. I leave the drain plugs totally unscrewed, but still in.
In actual practice, I install the seat first and then slide the mat & cushion underneath. Takes only a few seconds.
Gary
2014 Hobie TI
1984 Hobie Hawk RC Glider