Definify.com

Webster 1913 Edition

Noun.

The state or quality of being seaworthy, or able to resist the ordinary violence of wind and weather.

Kent.

seaworthiness ‎(uncountable)

(nautical) The property of a watercraft that makes it fit to go to sea.
The ship leaked like a sieve and rode like a barrel; in other words it was completely lacking in seaworthiness.

property of being fit to go to sea