What conditions must necessity be under?

1 The action was the only one practicable in the circumstances: Prager v. Blatspiel, Stamp & Heacock Ltd 1924. So a master faced with perishing goods has the right to dock at the nearest port and sell the goods for the best price he can get, as in Couturier v. Hastie. 2 The carrier or master had no opportunity at the time to obtain instructions from the owner: Springer v. Great Western Railway 1921. 3 The carrier or master acted honestly and in the interests of the owner.