TomD
If you are using it for the seats, that used to be a guttering/bottoming adze job. At the time I took courses their process was a little weird, there was one bizarre reversal, it went something like Adze, inshave, Crown plane, travisher. Normally a plane has the finest cut, but the Planes available were tighter radius than the travisher.

While nothing is any longer for sale, this is a good site to see the various tools.

http://www.drewlangsner.com/cw/Store.html

http://www.drewlangsner.com/cw/Adzes.html

I liked to buy the unhandled tools from drew as they were really high quality, and often had some interesting features like the Wegners tools he sold. Being in Canada, not having to pay for or ship axe length tools was great.

I like the medium length handles as you can brace against your knees for a very controlled cut.