I don’t know anything about how to get selected to ship but be aware that the AMO has numerous contracts which pay dirt wages and I don’t believe you have a way to find out what the pay will be before you decide to take the job.
Met a third mate working on a Maersk managed TAGOS ship here in Singapore yesterday and was simply stunned when he told me what his pay was and the length of the articles he had to sign on for! I am absolutely appalled that things have never changed since the 1980’s when Sea Mobility was running those ships (in fact, the pay was only a fraction higher for that 3rd mate than it was almost 25 years ago!).
There is absolutely no question in my mind that the AMO is in bed with these ship operating companies and puts the interest of them and the union far ahead of the rank and file mariners who pay dues to supposedly represent them. So beware that you might well be in for a shock when you do get your berth.