You could contact your lawmakers and ask for a crew bond escrow requirement for ships, insolvent companies forfeit the money and it pays to send the crew home with a year's pay.
I don't think any of the suggestions made thus far will do anything to help out.
I think that one of the only methods that has a chance is to go to the UN and work out a treaty on human rights for maritime workers with the stipulation that once a supermajority of nations ratify/adopt it, ships flying the flag of a nation that hasn't ratified it are not allowed in the ports of the nations that have.
