Thank you to everyone for your wonderful comments on my previous post.
This pattern is now available from my Etsy shop.
Tatting techniques used include ring, picot, chain, join, Catherine Wheel join, bead picot, and floating ring. It's written from the shuttle tatting point of view, since that's what I do, but the pattern should be do-able for needle tatters as well, and they wouldn't even need a Celtic shuttle!