I have a 55 lb thrust Motorguide I used for a brief period while my regular motor was in the shop. It pushed the boat along at what I'd estimate to be 2 to 3 knots. It even pushed it against a really strong headwind (whitecaps), and was making decent progress until the trolling motor battery gave out. Not that much of a drain, it simply wasn't charged up in the first place. There was a brief fire drill while I went below to get the primary battery out and get it hooked up. You drift downwind pretty fast in whitecaps. I wasn't really sailing that day....only moving the boat from point A to point B, but in anticipation that something could go wrong, I had taken the sail cover off and had double reefed the main and had it ready to hoist. I knew if the motor didn't have enough power or for any reason didn't work, I was going to have to get busy playing sailor! On a small lake for day sailing, I think it would work fine. Just be sure the battery is fully charged before you set out. A fully charged deep cycle battery should push the boat along at 2 to 3 knots for several hours. With any hint of a breeze, your sails would help you out as well. Howard M17, #278 Audasea