Legal Assistance for Industrial Airboat Lease

My corporation is leasing my industrial Airboat to the Canadian Government and Big Oil company's and am looking for a Canadian Lawyer with extensive experience with contract language to review and edit my contract to ensure there is clear language to protect my company financially and legally. Air boats have big 80" propellers that are spun by 500Hp Corvette Engines. They drive on ground, snow, ice, and water. Companies use them to transport people over thin ice on rivers and lakes and swamps. There is no industry standard for airboats designs and the varied terrain they travel in make them prone to severe damage. A new engine can cost $50000 and be destroyed in only 5 mins of operation. A $5000 propeller can be destroyed by having one branch hit it or a piece of small cargo the size of a marble can be sucked into it making in non movable. These boats have the risk of tipping with occupants in deep icy waters too. These boats are VERY rare and they are absolutely the best way to move people across swamp and thin ice when done properly .
I want the renters to accept the risk , have all maintenance and repairs done my licensed mechanics, and return the boat in equal working condition or... better condition than when they rented it.
Please help me put this into legal words that will stand up in court.