Are all US mariners paid USD 200000/mth.??? No wonder you can’t compete for jobs and there are few US flag ships in international trade. (In oversea waters for OSVs)
Of course most foreign mariners are paid less, but in most cases they are on permanent payroll, with even time and paid time off, 13th month holiday pay and other goodies.
There is also the security of having health care, paid sick leave, unemployment benefits, old age and disability pension etc. covered through a government system, not by your employer via an Insurance company that take a hefty fee in the form of overstaffed and overpaid management and greedy share holders who want their profit to be first consideration.
(OOOPS, sound too much like SOCIALISM!!!)
To work on Drilling Rigs, OSVs, or other such vessels operating in someone’s EEZ waters, will likely require some sort of visa/work permit. But for crew on vessels under foreign flag on short term contracts, or in international trade, there are no such requirements in most countries.
For a foreigner to work on vessels under national flags, whether that be OSVs or any other type of vessels, will usually require some sort of affiliation with the country. Taxes are also deducted, but it give rights to the same benefits as a national.
Coastal trade may come under Cabotage Laws and require citizenship. (Or in the case of Europe, citizenship in any EU/EEA country) For passenger ships and ferries it may also require language skills, other than English.
The problem with US mariners being covered by the Jones Act, even when serving on foreign ships in foreign waters, may be the biggest hurdle. But if US would adapt MLC’06 and scrap that in what in essence is supposed to be a Cabotage Law, that hurdle could be removed.