Boy you post some doosies! A crane or a construction extendable boom forkilft would be the cats meow for this. I would strap the car front and back. Depending on the injuries of the patient I would even consider hoisting the car onto the dock and then continue with extrication there! If the patient had a spinal injury suspected then extrication could be done by taking out the rear window to gain access and to cover the patient. The roof of the car could then be rolled forward towards the boat. after that the patient could be removed over the trunk.
With the equipment we have we would wench or come a long front and rear of the boat, attempt struts between the dock and boat. Then we would strap the car and gain access from the rear and cut or role the top...
Drain the marina of course!...Lutan you make a valid point. securing the vehicle to the boat and in turn to something"bombproof" on shore, would be my first priority. then the whole thing would move together(up and down). talk to the marina and shut it down no boat traffic in or out, i would also limit access to the docks and boats in the immediate area to only essential personnel. The idea is to keep the water as calm as possible to limit the up and down movement. unfourtunately i don't see any way to completely isolate the boat from rocking in the water. I would agree with daniel and probably move the vehicle to shore before attempting any type of rescue. it's not worth risking my crews safety. falling in that water between the boat, seawall,with an unstable vehicle above, now that's a big problem.
I don't know jack about boats but could adding ballast help to stabilise the boat a bit?
The up and down movement is going to be a real issue to be addressed as every single time someone so much as farts on the boat or on/in the car then it's going to move. Maybe even securing the car to the boat is going to create a bigger issue with the movement as it may possibly drag the car in????
Tying extra lines to the boat might help. Draining the harbor would work! The only way to counter the dipping and diving is to go overhead. Restricting movement in the area like Michael says is a great idea.
Nylon strap,fished thru the car forward of the B post.Fork lift,tow truck,or the marina yard crane to the rear of the vehicle.Method will vary slightly depending on which of these vehicles we use.Since I know tow trucks,I'd back up to the car,lower the wheellift,back up within 1" of the rear bumper,hook one side of the strap to each winch cable.Boom up.The front of the car will rise and the car will slide back until the bumper hits the wheellift.Raise the boom until the front wheels will clear the seawall,Lift the WL until the rear wheels clear.Drive ahead.Write healthy bill.Case closed
I'd add lines to the boat and tension them tightly, for starters. That wouldn't elminate vertical motion for the boat, but it would greatly reduce the chances of vertical boat motion dropping the car into the water.
I'd use a crane or large boom wrecker to support the vehicle, but I'd sling the car from a small boat in the gap. I'd use a pike pole to pass the sling so that the rescuers in the small boat didn't enter the fall zone.
Once the car was secured, I'd step chock the rear of the car, put my smallest rescuer in a harness with a belay, pop the rear window and enter. If the patients could self-rescue, cover the glass and see if they can crawl out - this wreck isn't likely to have a major mechanism of injury.
If a patient was seriously hurt or incapacitated, reverse flap the roof and bend it toward the boat, then secure it. Then cut away the front seat backs. You should be able to remove the patients through the opening at that point.
It is very unlikely that you would need a dash lift in this situation.