Inspection is a check of PHYSICAL condition of an item, such as inspection of Lifeboat or extinguishers (which you need to carry out physically). Audit focuses on past activities, detects faults, focuses on operations, system operation and documentation. Audits are not every thorough. Survey focuses on future activities so that the equipment continues to function in future. It focuses on physical status (eg a machinery which should be working in order for the survey to clear). Survey is more thorough in nature.