(1) Where a ship, without lawful excused, deviates from the voyage contemplated by the policy, the insured is discharged from liability as from the time of deviation, and it is immaterial that the ship may have regained her route before any loss occurs.
     (2) There is a deviation from the voyage contemplated by the policy--
         (a) where the course of the voyage is specifically designated by the policy, and that course is departed from; or
         (b) where the course of the voyage is not specifically designated by the policy, but the usual and customary course is departed from.
     (3) The intention to deviate is immaterial; there must be a deviation in fact to discharge the insurer from his liability under the contract.