Oil Tanker Economics, WSJ

Boom/bust for the oil tanker market too?  Here is Wall Street Journal:

“Low oil prices and surging production has been a boon for the 2,000-vessel strong oil-tanker business. The cost to charter tankers soared to near-record highs last year, while low fuel prices have boosted the profitability of ships.

One sign of the good times: Many ports are so congested with crude vessels that tankers are plying their routes at a slower pace. The average tanker in recent months has cut its speed by 10%, on average, to minimize downtime said Paddy Rodgers, chief executive of the big Belgian fleet operator Euronav NV.”

Here is the link:

http://www.wsj.com/articles/new-oil-tankers-threaten-to-spoil-global-maritime-industrys-party-1458039676

One question: is the slowdown due to congestion or are traders taking advantage of contango markets?