How do you "tone down" the shine on a piece of varnished furniture?

I am varnishing a piece of walnut furniture to protect which I am using as a Bathroom vanity, holding the sink bowl. Water drops are ruining the finish. So I am applying a spar varnish to the wood. I need to put 3 coats of varnish on to protect it. But even though I am using a satin finish varnish, the wood is getting more and more shiny with each application, as will happen when applying coats of varnish. Does anyone know of any kind of varnish that will “cut” the gloss?