Canada Rice Mills Ltd -v- Union Marine & General Insurance Co Ltd; PC 1941

Cargo was on a voyage from Rangoon to British Columbia and insured against perils of the sea. It was damaged by reason of heating occasioned when cargo hold ventilators were closed to prevent ingress of water in heavy weather. The Court of Appeal of British Columbia had held that the cause of the loss was not a peril of the sea because the weather encountered was normal, and such as to be normally expected on a voyage of the character, and there was no weather bad enough to endanger the safety of the ship if the ventilators had not been closed.
Held: The appeal succeeded. Lord Wright said: ‘these are not the true tests.’ Any accidental ingress of water into the vessel was a peril of the sea. The entry of sea water through an opening by which it was not supposed to enter was accidental even if the sea conditions were entirely normal for those waters at that time of year. Thus, storms that were seasonal and frequent, and therefore to be expected, nevertheless ‘are outside the ordinary accidents of wind and sea [and are therefore fortuitous]. They may happen on the voyage, but it cannot be said that they must happen.’