I might be missing something big, but this doesn’t seem like a degenerate course of action. I think this mainly because

1. It is a military vessel and thus has no reasonable protection based upon it being “peaceful”
2. The unfortunate reality is that the US is at war again in the middle east, and boats get blown up in war, especially when the US government has declared that destruction of Iranian navy is one of their goals.

Overall, I could understand the condemnation for the attacks from the perspective that the US shouldn’t be fighting an illegal war, but if you concede that point, the attack of an enemy military vessel irregardless of its current capabilities is a fully ok course of action.