Becoming a Tankerman in Texas

My wife saw an ad in our local newspaper here in Houston for a Tankerman for SGS. I’m interested in applying for the Pasadena, TX location as I live an hour away from there. The training lasts about 4 months and if all goes well you will obtain your Merchant Marine Credentials (MMC). If accepted, you have to pay for the training - $13,000 (yikes - that’s a lot of money). The benefits seem to be good and the pay they mentioned is about $60,000 per year. But I had a few questions: The website says you work 6 days and off for 3 with some overtime though it’s not guaranteed – is this accurate? Is overtime mandatory if offered OR is it optional? Is there a union? What are union dues like? Do you report to work for a certain time? Is it required that you live very close by? Is the pay range correct? Once you make your year mark – is it hard to get time off for vacations and such? Is SGS a good company? Does anyone have any feedback on the Pasadena location? Thanks everyone and I look forward to your reply.