Gentlemen and you know who you are,

I am building a countertop with alternating cherry and walnut strips
glued together. Due to the sink in the middle there will be some
water splashing around. I like the natural look of walnut and cherry
so no staining. Planning to use many coats of polyurethane for both
top and bottom surfaces. Water based or oil based? Anything better?
Since I have little experience with wood finishing, please do not skip
any steps you deem as obvious.

Peace.

Jim