The diving here is off walls and ledges leading from shore to the depths of the St. Lawrence River. It is salt water, and often times freezing cold right through the summer months. I experienced several thermalclines diving in late August, and noticed several "fresh water surges" that dropped the temp noticably for a few seconds.. and disturbed the visibility with a hazy halocline.
Marine life is abundant, though it seems not as varied as we see on Deer Island, NB. There is no lack of subjects however, and the "knobby" anemones are rather fun (and not seen in local NB). The soft coral is everywhere! I did not see any Basketstars though.
Access to the dive sites is from shore, and is available from the marine park established in Les Escoumins, or from a nearby campground. Care must be taken to control depth, as the ledges can allow one to descend quickly.. and depths of 100ft+ are easily reached. Visibility is good, I've seen at least 20ft each time I've went there.
The presence of whales moving through the St. Lawrence is a top-side treat.. watch for Belugas!