Defying Iran and heading through the Strait of Hormuz is a gamble. But like all the best gambles, it is a lucrative one, so crews are inclined to fancy their odds. To counter the high insurance costs for buyers, countries such as Iraq and Qatar have been offering crude oil at steep discounts. “People just assume one ship in 12 or one ship in 15 is going to get hit by an Iranian drone, but you make enough money on the rest of them,” said Rory Johnston, founder of the market research firm Commodity Context.