Moby Dick is formerly a home-made scrub plane I re-shaped into a compass plane for hollowing the seat.
I'm not counting this as a new tool since I spent no money to convert it.
I laid out the part of the seat to be shaped by sitting on it, and tracing around my bottom. I then used a compass to even out my markings a bit.
|Will Moby Dick work?|
|Seems to work great across the grain.|
|Clean up with a scraper.|
Fine tuning the seat.
View the rest of my build here.