Fascinating article in FACETS about the Changes in shipping navigability in the Canadian Arctic between 1972 and 2016 by Luke Copland, Jackie Dawson, Adrienne Tivy, Frances Delaney, and Alison Cook:

Analysis of ice navigability patterns across the Canadian Arctic indicates that it is becoming generally easier for all ship types to navigate this region up to the present day. In particular, there are many regions where the least ice-strengthened ships, such as Type E pleasure craft, were previously unable to navigate in the 1970s–1990s. For example, there were few periods when pleasure craft (Type E vessels) were able to transit through the southern route of the Northwest Passage until the 2000s, whereas recently >20 pleasure craft per year transit this part of the Arctic (Dawson et al. 2016; Johnston et al. 2017). Navigability conditions for cargo resupply (Type B) vessels are also easing, which helps to explain why vessels from eastern Canada have been able to resupply western Arctic communities by transiting through the NW Passage since ∼2000 (Dawson et al. 2016). However, sea ice conditions are still highly variable from one year to the next, meaning that a voyage through this region can quickly turn to disaster for poorly strengthened vessels with inexperienced crew, particularly for pleasure craft (Washington Post 2017).