too great amount of detail.
the picture is 1200x800. I had to put glasses to see some of the details.
to print it on a t-shirt you'll need to reduce it and add the text and eagle.
to print it you''ll need as few details as possible.
are you sure that you're not asking for the impossible?

does it need to be vector?

just asking.
 

take a look at these two companies and see if you can match or beat there designs,www.7point62design.com,www.vision-strike-wear.com then come back to my design and see what you can do.

Does the design need to have the background colors of the sky and ocean blues or can that be the color of the t-shirt it's printed on?

How much of the T-shirt are you wanting to see covered?

Do you want this design to match the "gritty-ness" of the examples on the other sites?

as you seen on 7point62design the t-shirt designs are bold there up in your face,that is the style i want for the design,
 Looking from a printing side of this, is if you use a color t-shirt your limited to that color t-shirt, if the background has it''s own color than it opens up a wide range of colors to choose from. 
Tom