Curt: Re my previous post, I should have asked the size of your vessel before suggesting other routes; You will have no problem on the St. Lawrence in a 77' foot vessel with a speed of 10 knots. If you need more detailed info feel free to email me offline. Regards Bob Keltic Marine Group Keltic 48' Keltic 65' Keltic 74' Seahunter Patrol Boats www.kelticstar.com