Score one for the Navy

It's never a good idea to fuck with large naval vessels and, whoever this was, they learned the lesson the hard way. Cindy Ok has a Slate article about the incident:

A Navy ship fired on an approaching boat in the Persian Gulf, killing one and injuring three other passengers, a U.S. military official told ABC News.
A Navy spokesperson told the network that the oil supply ship USNS Rappahannock's security team fired a fifty-caliber machine gun at a "small motor vessel after it disregarded warnings and rapidly approached the ship" off the coast of Jebel Ali, the largest port in the Gulf region.
The official said that the vessel was, in the words of ABC, "a white pleasure craft". United Arab Emirates officials, however, said that it appeared to be a fishing boat. Regardless, the course of action taken by the security team— which included at least one warning shot— was described as standard procedure for Navy ships in the area.
The incident remains under investigation, although no one appears to suspect terrorism or any involvement from Iran, which has a history of harassing American ships in the area. "I can't emphasize enough that this has nothing to do with Iran," the official told ABC.

Rico says yeah, an aggressive boat just happened to be wandering around in Gulf waters...