Not necessarily. Ordinary, healthy ships are damaged by wave action, but the waves in question are rare. Conversely, if a ship has been exposed for many years to the kind of loading that results in metal fatique, failure will eventually occur under circumstances well within design and operational parameters. Yes, there is a discontinuity -- or nonlinearity if you prefer -- to that kind of behavior. Everything appears all right until suddenly it isn't. But that doesn't mean that some suspiciously overwhelming condition suddenly arose. It doesn't have to be an unusually strong storm wave to precipitate failure under degrading capacity.
Suppose I have an account that must maintain a minimum balance in order to avoid penalty. Let's say I've neglected that account, and a small fee is being levied against it every month that I haven't noticed. When the debit of that fee on some particular day causes the balance to drop below the minimum balance, a penalty suddenly becomes due. That's a sudden change in the state of the account. It's not because the periodic fee was large. It's that it was relentless over time, and eventually reached an enforceable point.
