The mission of the Institute of Heraldry (Fort Belvoir, VA) is to "furnish heraldic services to the Armed Forces and other United States government organizations, including the Executive Office of the President."
I saw that...Is there something that actually requires the CG to get the Army's approval for such items though or is it something that the Army does when a CG cutter requests it?
It is a service provided by them. (NOTE: at a fee, which is well worth it!). They did the WILLOWs when we commisioned her and did a great job with it. They incorporated sybolisms from previous Cutters with the same name, the homeport and the new Cutter. They provide a detailed explination of every little bit they put on there.
The Institute of Heraldly is also responsible for the development and final approval of the five service's new medals and ribbons (U.S. awards only, not the foreign ones).
When I was the XPO on ABBIE BURGESS (WLM 553) we went through the heraldry for our coat of arms. For some reason she is not listed on the page of Coast Guard Cutters. I have a copy of it here somewhere, let me see if I can find it. The CO had the Passamaquoddy Indian tribal leaders translate 'Downeast Tender' into their language. If I can find it I'll post it (or a link to it) here.
Seems to me as though there is a light house and a lobster on it too ... the lighthouse was the one our namesake operated.