Hydraulic jackplates are a great asset when obstructions are at a higher risk level. I get to move my propshaft vertically 5 inches when idling, decreasing the amount of stuff I might hit. Add in some trim, and my skeg/prop are exposed to impact even less. In my case, the exposure of lower unit and prop below the pad is only the the bottom 5 inches of arc, if that. Even then, it's at an angle so that it tends to slide off what it bumps into. I still carry a spare along with what's required to change it. I also have a spare prop washer/nut kit in the boat's toolbox. I'd hate to drop a critical part even in shallow water/mud while changing one.