When is the employer required under The Merchant Shipping and Fishing Vessels (Health and Safety at Work) Regulations to introduce health surveillance of workers on his ship?

Where risk assessment identifies that: (1) a particular work activity may cause ill health; 

(2) an identifiable disease or adverse health condition is related to the work; (3 ) recognised testing methods are available for early detection of an occupational disease or condition; (4) there is a reasonable likelihood that a disease or condition may occur in relation to particular working conditions; and (5) surveillance is likely to further the protection of workers’ health. (Reg. 11)