Larger non-union companies have Health insurance. Smaller companies often do not. Some seasonal employers provide year round coverage, some do not. The amount the Mariner has to contribute toward a company health plan (pre-tax dollars) varies from nothing to quite a lot.
A young mariner can buy good personal health insurance (with after tax dollars) for about $600 per month ($20 a day). An older Mariner might spend $1800 a month ($60 a day), unless he is 65+ and on Medicare (government provided old age insurance). A 65+ Mariner will probably still spend an extra $150 to $500 a month on supplemental health insurance.
The quality of health plans and what they will cover varies a great deal, as does the time required to obtain pre-approvals from the insurance company for treatment. Many medical treatments are not covered at all. Typically, bariatric surgery, cosmetic surgery, “experimental” treatments (insurance companies call many common and proven treatment “experimental” to avoid paying), dental, eyeglasses, and hearing aids are not covered. Dental insurance, and eyeglass insurance are sometimes available separately, but they are a worthless ripoff.
In summary, the value of union or employer insurance benefits is only $20 to $60 per day, which is not much of a benefit when tugmaster wages are at least $200 a day less than they should be.