With good working, properly sized and located propulsion equipment aboard our minimally sized Toy Boats; and with a competent pilot at the helm there should be little reason for collision or grounding. Twin screw is a plus in this regard. But single screw can also be made to respond for emergency maneuvers. Basically it means: Take it slow in the first place, give wide berth to others, and be ready to apply momentary power and applicable shift/rudder alterations for quick boat placement alterations or to immediately attain a dead stop or even a fast reverse mode if necessary.
Keep you eyes and ears wide open at all times!