If it was a sticker may be,but to engrave such an emblam on a US navel ship I have my doubts,the sonar would pick up the sounds. It would also take too long to engrave such an emblam. Even just a sticker,just goes to show how cunning the Iranians are.
Rohani: Nuclear deal achieves Iran's goals (AP)
from the article: Iran Revolutionary Guards: Unit engraved emblem on U.S. ship