First off, be sure to thank your brother for his service, sacrifice, and commitment. And be sure to let him take long showers, eat properly cooked meals, and to dress very casually... all pleasures that have probably been denied him for a while.

As for the emblem. You could model the U.S. flat then use non-linear bend deformers to match it to the globe surface. The rope could be a cube face extruded along a path (if you extrude it with enough divisions and turn on twist). The anchor could be an extruded and beveled polygon shape. The bird could be a pain if you're wanting to model all the feather details. Notice I use "could" often, thats because there are any number of ways to get the same results.

Here's a larger googled reference with clean lines: https://www.msiac.dmso.mil/journal/graphics/PMTR24.jpg
I can sent you larger reference in vector or rastor format. I run a Navy Graphics shop, so we use this emblem a lot.
mhcannon@hawaii.rr.com