I saw this ship during a trip to Oslo a number of years ago. It is awe inspiring.
You know, being from a place far removed from oceans and large bodies of water, I never paid much attention to sea-faring vehicles.....other than that the ferry bearing me from Folkestone to Calais, or from Stranraer to Belfast, or the boat to Lerwick, all seemed pretty big to me.
I remember near Portsmouth, England, seeing a whole bunch of beached submarines--obviously decommissioned and having sat there a while, rusting and cannibalized--which on the other hand seemed pretty small to me.
On the other hand, being from where I am, I tend to think in terms of a football field, something 100 yards long, on which I sloppily and casually base perceptions of both length and height (such as in buildings).
One wonders if the largest-known Viking ship would have stretched a third the distance of a football field, or more, or less.