Kirby booked a profit of $75.0m in the quarter, beating the $61.3m of a year ago.

Earnings per share of $1.31 edged ahead of Wall Street expectations, says Michael Webber of Wells Fargo.

David Grzebinski, Kirby's chief executive officer, said: "We were pleased with our second quarter results. During the second quarter, we experienced continued high utilization and strong demand in our marine transportation markets.