I've dived a few different sites off Brockville so have an idea what that region is like. I'm considering a slightly shorter drive from GTA to the Kingston area for diving this summer and wondering how the diving there compares to Brockville, especially in terms of water temp, currents and marine life plus quality of wrecks.
Water Temps:
Brockville - Warm, no thermoclines
Kingstopn - Cold, and several thermoclines from surface to depth where the great wrecks are
Currents:
Brockville - 1- 2 knots
Kingston - almost none, but start becoming slightly noticeable as the lake ends, and the river starts (at the Wolfe Islander for example)
Marine Life:
Brockville - easier to find because fish like to swim into the currents to catch food
Kingston - Lots but little to none at depths where the wrecks are
Quality of wrecks: This one is a little more subjective
Brockville: many broken up due to currents, aggressive diving, warmer water temps, etc
Kingston: Many wrecks in pretty pristine condition due to colder water, deeper waters also less damaged by weather & ice
Because of the current and particulate travelling by at you doing 3 km/h the viz in the river is less than it is in the Lake. Viz on wrecks in the 80-90 foot range can sometimes have viz of 50 feet or more! (depends on where the thermoclines are and other factors)
I've been diving both areas for 35 years and they both offer something, just different! I won't get into the water for a good Kingston wreck dive without my drysuit, and do most of my diving in Brockville area in a 3 mil.
Hope that helps.
