unsinkable

Titanic was supposed to be unsinkable, designed to stay afloat even if four of its watertight compartments flooded.

Now, if one of those reference librarians can just help me figure out how to fold that fitted sheet, I’ll have an unsinkable smile too.

“There was absolutely no problem with it. If water hadn’t surged in, it was unsinkable.”

The ship had advanced safety features for the time and was famously said to be unsinkable.

The peninsula is of high strategic importance as it is essentially an "unsinkable aircraft carrier", says retired Ukrainian Navy Captain Andriy Ryzhenko.