The real issue, it seems, is that modern sonar is more dependant upon GPS and digital maps than what can actually be detected in real time. The extraordinary number of false positives it throws up results in a 'crying wolf' attitude amongst mariners.

Apparently the 'uncharted rocks' that gouged a hole in the ship could have been seen by a sailor's MKI eyeball had he taken the trouble to look over the side...

As for the Company's liabilities, the expression 'joint responsibility' springs to mind. I would expect the law of any country to be somewhat similar in that respect.