Hi Lou,

There's actually an easier solution.

Your center seat is suspended by two aluminum brackets. You can very
easily re-mount the seat. Unless you really want a kneeling thwart, it
would be easier and probably more comfortable just to shift your seat
around.

What you will need to do this is a drill, a drill bit the size of your
pop-rivets, a pop-rivet gun ($10-$20 at your local hardware store),
some pop rivets (usually comes with the gun), and a hack saw (or
something to cut the bracket)

The following assumes you have aluminum gunwales, but the same
principle holds true for wood.

Look at the rivets which hold your gunwales in place. I believe they
are 3/16", but they might be a different size. You will want to buy
rivets that are the same size, and a drill bit to match. If you have
black trim, don't worry. We-no-nah just sprays plain rivets with black
paint to make black rivets, and you can do the same.

Where your seat is mounted, the rivets which hold your gunwales on
also hold the mounting bracket in place. Drill out all the pop-rivets
on both sides in the section where your seat rests, you don't have to
remove the gunwales, just all the rivets holding in that seat bracket.
It should be 4 or 5.

With the rivets out, push down on the seat. It should pop out,
brackets and all. Remove the seat from the brackets.

Find where you would like the seat re-mounted. If necessary remove
more gunwale rivets in that area.

If you want the seat mounted higher, trim the bracket at the top
(where the rivet holes are) to the size and angle you want the seat to
rest at.

Mount the brackets by using the existing pop-rivet holes and perhaps
adding a couple extra to help support the frame. When the frame is
where you want it, just drill through the plate at the existing holes,
and add the extra holes when the plate is sitting where it will be
mounted.

Pop-rivet the brackets in place. If you want the rivets black, I take
a Q-tip and use it like a little paint brush, it even gets inside the
hole on the rivet.

Re-mount the seat. You will probably need to trim the sides of the
seat a little, especially if you move it back. Re-drill new mounting
holes, and you are good to go.

This is all a lot easier than it sounds, and should take all of 20
minutes.

If you have any questions, please feel free to e-mail me and I can
send you some pictures of the process. I'm about to remount the seat
on a Royalex Rendezvous (it is too far forward), so the pictures will
be of that, but the process is the same.

As for determining the height, that's such a personal preference I
doubt anyone can give you a precise measurement. On kneeling thwarts I
have seen them up flush with the gunwales, and on 4" drops. It is
whatever is comfortable for the paddler.

If you want a thwart instead of the seat, you can still use the
brackets you have and trim them down. It will be a very solid mount.

Eric