Vixen
Penultimate Amazing
And vanishingly unlikely IMV, especially if there was a crewman close to the ramp at the time. Who on earth would come up with a plot like that? They seemingly needed the ship to sink, but also needed it to look like an accident. So how big a bomb dare you use? What then were the chances the sabotage would fail, and what were the chances that survivors would report the detonation?
It's a stupid risky plan and what's the motive anyway? Do you need the Estonia to sink, or do you want to kill some individuals, or destroy some cargo? If it's cargo, how can you be certain that that particular cargo will be on that particular sailing? Why not just go after the cargo directly, or the people transporting it, instead of this elaborate high-risk sabotage?
It fails the Dr Evil test: If you brought this plot to Dr Evil your chair would tip straight back and drop you into the mutant sea bass tank. Some other henchmen would be tasked with just killing the cargo smugglers.
And look who the crew member was who made a statement he was at the car ramp at 1:00 when he heard a huge bang which caused the ship to swell up and almost knock him off his feet. This crew member changed his story many times. He was jailed a couple of years later for drug smuggling. The prosecutor wanted eleven years. Just sayin'.