Celtic tree of life on a nautical card?

Tree of Life Knot, sort of ...

I knew I wanted a knot tied on the bottom of this one, so I googled celtic knots and came up with this  utube link.  My plan was to do it in baker's twine, but I pulled out the kitchen string to practice. However, I think the kitchen twine looks just fine, and to do it again with baker's twine might mean another hour --- these cards are supposed to be finished in 45 minutes or less. Luckily I am on the VSN design team so we got the challenges early.

The challenge wasn't the knot!  The challenge here was to use a sponge to create a background. I have some cheapie sponges from the dollar store that are all cut up and in a jar on my table, so that part was easy peasy!