Tom-
I wouldn't use Future for still or deep water.
I had two bad experiences with Future. First, after a couple of coats, each thin pour (which took DAYS to dry completely) developed little holes or flaws when drying. A new coat would fix that one, but leave one somewhere else. I put probably 4 coats on that way until I gave up.
Finally, I poured Envirotex on the top after letting the future dry for a week or so. This worked and looked great, until bubbles the size of pinheads formed between the Envirotex and the Future after about two months. >
You may have better luck than me, but you won't find out until it's done for awhile.
I would use Magic Water if I had any still water to do right now.
Hope this helps,
-Phil