International benefits for us companies

I work international for ECO. ECO does not pay social security or medicare. This is legal and they are up front about it. My question is whether this is normal practice for all boat companies? In other words, do guys working for Hornbeck, Seaorp, etc. who work overseas have Social Security and Medicare taken care of? ECO tells us that it actually benefits us because we save 7.5 % employees contribution but of course the real reason is that Mr. Gary does not want to pay his 7.5 % share of the tax. It is pretty scary to look towards retirement with underfunded social security and no medicare. My current choice is to go back to the GOM (which I do not want to do), forgo a topped up Social Security and maybe not have a medicare plan, or to find another company that does not try to save a buck on the backs of its workers by not paying social security. Any information would be appreciated.