This article on the Northwest Passage caught my eye in the Guardian the other week. Quite a balanced report. The accuracy of the charting in Canadian waters is coming under increasing scrutiny as more ships sail in the Arctic. It's a national dilema. Hydrographic surveying is very expensive and governments cannot afford to survey every square mile of their territory. They have to focus their efforts on those areas which are most used. Advice from the Canadian Coastguard is here.
Does 24 cruise ships in 7 months count as heavy use? No. But if one of those runs aground and has a fuel spill which causes $millions to clean up who pays? The government (in the first instance). Risk versus cost. The universal dilemma. Should those ships who use these areas pay for the charting? A nice idea but cost prohibitive I suspect.
The Russians are using imagery to advise on clear routes through the ice. Certainly no replacement for navigational charts (of whatever source data vintage) but anything helps. I suspect forward looking radar are the best bet but even that didn't work for HMS ENDURANCE the other year.