water@oil

I know this probably been discussed a zillion times, but I miss the attention, plus it's been awhile since Doug has givin' me a razzin. I'm still a few weeks away, but I'm trying to plan ahead. I have pine beadboard panels on my exterior and would like to darken it a shade or two, what would hold up to spar varnish better, water based, or oil? I thought I saw somewhere water was better, but I have never really used it. I will cover Mollie's ears while you all dig into me 
