Sealer Recommendation for New Pine Deck

I have an oceanfront house on the Outer Banks of North Carolina. I am replacing about 3000 sq. ft. of sun decks, porches, walkways, and steps. I am using high quality treated pine 2x6 deck boards. (This is C grade lumber (two steps above #1) that is commonly used for floors and trim.)

What is the best sealer for me to use? I don’t care about “staining” the wood, nor it turning gray. I simply want to prevent the wood from water absorption and “checking.” I would like to apply the best “sealer” available as we install the new decking. I then plan to re-apply the sealer every couple of years for ongoing protection.

Thanks for your help…..