Yes. back in the late 50's Mercury used "Lake X" in Florida for their "brutal" engine testing. Driving their engines over sandbars, logs, concrete bridge railings and such told them that they needed something to soften the impact of the spinning propeller, once airborne due to the LU hitting an obstruction, from ripping out the transom or such when it re-entered the water at something well over the max rpm rating of the engine.
So they added externally mounted shock absorbers between the transom clamp bracket and the engine's mid section. Fast forward. Time to do something better. Make the shock absorbers hydraulically powered cylinders. So they added a hyd. pump and hyd. lines to the replacement cylinders where the shocks were once mounted. I had about a 1974 year model Merc 850 with such an arrangement....worked great. Along that line they also added a kill switch, probably a Mercury (metal) ignition kill switch to the mid section such that when it kicked up the Mercury moved and disconnected/shorted out the triggers to the engine.
