Well, doing a review for the entire St. Lawrence river could be lengthy since it's diving possibilities cover literally hundreds of miles but here are a few comments and highlights. Start in Clayton, NY and do a shore dive on the Wreck of the Islander. See the review here on ShoreDiving.com as with any wreck I mention. Next, make your way up to the Prescott, ON area in Canada (about 1 hr drive north and east) and shore dive the Conestoga (locals call it the Connie) and also dive the wreck of the Rothesay just a few miles away. All three dives I mentioned are easy/shallow shore dives but still hold much interest for advanced divers as well. Current can be an issue at the Connie, and, if you do dives from a boat, the current can really rip (Cozumel Like) in places and at certain times. Shore diving the St. Lawrence river is a great weekend trip for NE US divers. Stop in one of the local dive shops in ON, Canada and you can get air fills and even more info about other shore dives close by (none as exciting but still ok) and also info on doing one of the frequent boat dives. There are more shore dives than you can do in a long weekend unless you really go all out. Enjoy!!!