[Drill Thrawl]

It would cause a leak if they ignored the vibration long enough. And judging the intelligence of these "people" I don't think that is out of the question.

Shame we won't get to find out either way.

[PDGearhead]

True enough, but we had a blade break on one of our propellers on our power boat at cruising speed and the vibration was immediate and severe. The prop was a large, three bladed propeller and apparently there was a defect in that allowed one blade to break near the hub.

We immediately stopped the engines to determine what had happened. We continued on home on one engine. Although the vibration and shaking was severe (for the few moments after it happened and before we shut down), there was no damage to the cutlass bearing or shaft log.

So, it would be very unlikely that they would have any additional damage since they would immediately notice a vibration when they attempted to leave the dock. If the shaft is cut, then no damage could occur since the prop will not turn and the vessel would not go anywhere.

Actually, cutting the shaft is very effective in disabling the ship safely.