: What you are calling hip plates actually derives from the struts
: that fiberglass boats use to hang fiberglass seats. They
: automatically worked out as a brace to keep your hips from
: sliding side to side.

: Yes, you can pad out the sides with foam to achieve the same. I
: usually make "hip struts" and run them from the deck
: to the floor of the boat. I use the space between the plate and
: the hull to store my pump. You should have some sort of hip
: support - but not too tight. A hands width of space is good. You
: want to be able to twist and turn a bit in your seat but not be
: sliding from side to side out of position. if you decide to
: learn to roll and even for leaning the boat with various
: techniques, they are a necessity.

Got it; Thanks!