If you are violating the Jones Act, the Offshore Marine Service Association (OMSA) is ready to put you on blast.

Promising that "we'll be watching", the US offshore trade group is launching the 315-dwt Jones Act Enforcer (built 2007) — a ship it intends to use to document and publicise what it considers violations of the cenutry-old cabotage law.

"The Jones Act is very simple, if a foreign vessel picks up cargo at one point in the United States, and takes it to another point, it has broken the law," OMSA president and chief executive Aaron Smith said.

"Foreign vessels have succeeded in confusing this issue for a long time. Now, we're going to shine a bright spotlight on their actions and show everyone just how many foreign mariners are taking money out of US mariners' pockets.

"If foreign vessel owners or the companies they work for don't like this scrutiny, I suggest they hire US-owned, US-crewed and US-built vessels."

The OMSA said the converted passengership will gather photo and video evidence by both sea and sky and provide it to authorities, the media and the public.

Specifically, the OMSA — which counts Tidewater, Seacor Marine and Harvey Gulf International as members — takes aim at what it calls loopholes in the law created by "unelected bureaucrats" in Customs and Border Protection (CBP) stretching back to the 1970s.

These alleged loopholes involve CBP interpreting the Jones Act to allow foreign-flagged ships to transport items to offshore oil facilities on the outer continental shelf or too narrowly defining the term "merchandise" in the text of the act.

The OMSA said CBP has acknowledged issues with their rulings, but has so far refused to remedy them.

Supporters of the act — which mandates all goods carried between points in the US be aboard US-owned, built, crewed and flagged ships — say the law creates jobs for US citizens and protects the country's national security interests.

Opponents argue, in part, that the law needlessly increases costs for consumers.

"The act is not being implemented in a manner that is correct under the law and as a result American security is being threatened and American workers are losing jobs to foreign vessels," Smith said.

"It's time that someone takes a stand and that's exactly what we're doing."