The test and the Marine Corps guide are so similar!! Honestly, if I'd had known how close they were, I would have gone through the questions a little quicker when taking the test. I ended up running out of time because I would double check wording. Know the math questions cold on the study guide, it will really pay off because you'll know how to work the problems with different numbers. Very important!!! Nautical, I did a little internet research, looking up basics, don't go to in-depth (right of way, lights on which side). My research helped me to make quick, confident decisions on the nautical questions. Aviation, know what the guide says you should know, and you'll do great. Good luck on spatial though!!! Man was that completley different from the ARCO study guides. Nothing can really help you with that, but just know everyone has problems with it.
There is already a lot of discussion about this topic, and some people have even posted which questions from the guide were on the test. Right before the test, I focused all my attention on those posted questions, and ya, that helped a lot. Know those problems cold. Good luck.