Public liability exclusion of risks insurable in the marine and aviation markets. The exclusion is of liability arising out of the ownership, possession or use by by the insured of aircraft, hovercraft or watercraft other than barges, motor launches and non-powered craft used on inland waterways. The ownership or use of small craft is not excluded. Also the insurer modifies the exclusion so that any contingent or vicarious liability associated with craft not owned or operated by the insured is covered.