I'm a bit jealous, as this is one of the best times of the year to dive the Gardens.
I was fishing with my wife and boys out of Freeport last weekend. We went out about 50 miles, working around some wrecks. Looking down, the vis looked perfect. When we were trolling, the wash from the props was cobalt blue and from our perch on the tower, we could see fishing hitting the drift baits, even when they were ten to fifteen feet down and several hundred feet behind the boat. I bet the diving visibility was 50-75' feet. Based on that, I reckon you guys will see 100' plus on the Banks.
For us, the seas were flat most of the day, rising to 2-4' in the evening. Perty darn good conditions, but about normal for this time of year when there are no depressions around........
I kinda wished I had my dive gear with me, but my wife would have been p-o'd if I'd jumped in and left her on the boat with the kids........
(Hey, don't forget to take dramamine, or whatever you use, THE NIGHT BEFORE, when you get to the boat and before you go to sleep, then redose in the morning. It seems to work for my wife and kids.)
(btw: the fishing was great. My 9yr. old caught a 42lb. Ling ("Lemon Fish" to my coonass wife. Cobia to folks in Florida.). Between both boys, we caught 5 King Mackeral, a mess of big (legal) snapper and the Ling (Daddy was mate...no fishing for him.) We could've caught more, but I like my fish fresh or fresh frozen, and that was enough for us and the crew.
Have fun! Dive safe...