Depending on the carrier, life on board a cargo ship can be either enjoyable (with some larger ships having swimming pools!) or difficult. The ILO published the following video about some of the practical changes brought about by passage of the Maritime Labour Convention.
Of course, the United States of America is not a party to the Maritime Labour Convention. Indeed, America has had its own protection regime since 1915 in the form of the Seamen's Act. The Jones Act, which supplemented this legislation in 1920, added, inter alia, additional rules with respect to workplace injury compensation. Since the Seamen's Act and Jones Act were regarded as too onerous for many U.S. shipowners, this began the process of flagging ships out to less well regulated foreign jurisdictions, many of which are catching up, through the Maritime Labour Convention, to the standards set in the United States of America.
A bit of trivia: the U.S. Supreme Court once awarded a sailor $302,790.40 when an ocean carrier failed to pay $412.50, see Griffin v. Oceanic Contractors (1982). Griffin, the plaintiff, sued his employer for the $412.00 the company docked him for the cost of his plane ticket home when he was fired by Oceanic Contractors, the defendant, after he was injured on the job. The Jones Act allows a seaman to recover double their wages when the wage payment is delayed without sufficient cause. The litigation began in the trial court, then went to the Court of Appeal and, finally, ended up before the U.S. Supreme Court. Both the lower courts found that Griffin was owed the double wage penalty from when he was fired until when he found a new job (34 days). However, the Supreme Court held that both a plain language reading and the legislative history of the Jones Act led to the conclusion that the damages were meant to be punitive, not just compensatory, and therefore it was not unreasonable to hold the company liable for double the wages for the entire four year period from when the money was withheld until when the company lost the case and ultimately paid.
The Maritime Labour Convention, by contrast, stipulates a relatively mild 20% per annum interest rate for wages not paid to the sailor without reasonable cause on the due date.
Of note, of course, is the fact that any U.S. ship that makes port in a country that has ratified the Maritime Labour Convention will face the legal reality of being forced into compliance. Thus, conceivably, a non-compliant American vessel could be detained in port.