Dove with Seeway Vision (http://diveseewayvision.com
) in mid-July. Water temperature in mid-70's, viz around 70 feet. Operator was first rate; crew even carried gear from/to unloading/loading area to boat. Intact wooden wrecks, some marine life, interesting geology. Whenever possible, all dives finished with a drift dive, some as long as 40 minutes; if you were lucky, a freighter passed nearby.
There are several dive operators in Brockville ON, whose highway signs herald it as a dive destination. It is. Many of the operators have arrangements with hotels that discount the prices.