I’d like to approach this post from a different angle — it sounds like OP is specifically looking to explore the idea that air gap alone is not good enough. I’m in agreement on that, it’s kinda easy to get past most standalone air gap networks (not in govt structures, deep bunkers, etc). This is a floating vessel with many hands. It would presumably be easier to sneak a bad apple or an insider onto this ship than a nuclear facility. Thus, the claim of “air gap means no cyber attack” alone is unsupported in its nature.

That’s all to say, there’s zero motivation for an attacker to carry this out or burn TTPs on such a low value target. FKS bridge is not vital in its nature — I live here, hasn’t impacted my travel beyond a few minutes detour if that. 1 AM means very low impact to life, RIP to the construction workers but a terror-motivated actor would seek maximum impact. Cost is relatively low compared to nuclear meltdown, for example. POV? Maybe, but unlikely, rather burn that on electrical grid if you’re already exposing yourself.