My new Hobie Adventure Island tends to scoop up water through the lifting handles when healed over. The water collects in the seat well. Also the drain plugs leak. The plug threads are incomplete and the "O" ring might not seat well.
I am 6' 2" and the seat back sits low on my back. To solve the drain and support problems I decided to raise the seat. Since there are no plug holes I had to drill through the back of the seat well.
To add some support to the lower back rest I added a polyethelene pad. This might be a little overkill.
To raise the bottom two 1.5" foam pads under the seat.