Use 2 props. 1 for light load. Other for a crowd. Go to 4' of water. Jump in and change the prop. Havs spare nut and washer if needed. Been there many times.
Why can not 2 people back the boat in just far enough to get it on the boards or guides? Then back in the rest of the way ? I can do it alone. With a person in the vehicle and a driver in the boat. Both on cell phones. Done