Some phenomena peculiar to warmer oceans have been known to impede identification and localization of subsurface contacts in the Arctic. There are more temperature layers, with more pronounced boundaries, than in warmer water. Although refraction through the actual boundaries between the layers creates a lower probability of detecting signals outside the layer in which they originated. The ice noise degrades the performance of hydrophones to the extent that it is sometimes difficult to discriminate between target and ambient noise levels. Detection ranges are short unless a target is exceptionally noisy.
Modern submarines are very much quieter and radiate very little noise except at very high speeds.
These factors further affect the reliability of automated detection systems due to the difficulty in positively matching received target signal with preprogrammed criteria. Because technology designed for general use does not necessarily produce acceptable results in the Arctic, requirements for that region frequently have to be addressed independently. The occasional passage of hostile, submerged, war-vessels for strategic positioning in the northwest Pacific or northeast Atlantic is what Canadians are most likely to be challenged with in a time when the peace is seriously degraded, or in wartime. If we were to ignore that possibility, others who would be put at risk by that neglect would have to assume the task of monitoring and protecting access to the Canadian Arctic. Considering the current argument with the United States over Canadian Arctic sovereignty, it would be wiser for Canadians to take the decision, make the investment, and assume complete sea control of our Arctic waters.