I guess if someone chose not to strap their boat to the trailer, the boat could bounce up, the hinge on the device would allow both boat and motor to move upward. Then when the boat came back down the hinge would allow the device to follow the movement of the boat. When the boat came back to rest on the trailer, the momentum of the motor would ordinarily put great stress on the transom. With this device, that force would be transferred to the trailer instead. So it would still do its job if the boat wasn't strapped to the trailer, although abviously that's not the point of the design. If you put a brace or "transom saver" between the motor and the boat, it may keep the motor from bouncing, but would do nothing to take the downward and rearward stress off of the transom. Same with strapping the motor down with or without a block of wood. (Thats my rig in the pictures, by the way
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