Just how bad are a Sub Captains wages?

Having just watched this film which was an enjoyable enough thriller I found myself put off at the beginning by Jude Laws living standards. If he had been in the Navy for 15 years and then in civilian salvage as a captain for at least eleven years why the heck was he living in a grotty council flat and driving in a beat up old car? Even taking into consideration him being taken to the cleaners by his ex wife when they got divorced his standard of living would have been leagues ahead of what is shown in the film. According to the quick look I had via google the average ships captain earns between £50 to £100 thousand pounds per year that kind of income is enough to buy him a mansion in Scotland!