Actually I started with the typical 1 1/2" x 3/4" gunwale, then glued a 3/4 square piece inboard at the top.
Since I then cut the radius on the upper outside surface, some of the extra weight was removed, but not all.

As I said this was just for the look.

I'm embarassed to find I didn't get a really good picture. Here is the best.
You can see on the left the "add on" piece, on the right is the rounded gunwale after planing - not fully sanded out.

You might notice I don't cut the tabs on the bulkheads to capture the stringers. They have dowels and are epoxied in place with fillets.