[Tax-chick]

Examination of the tree rings will give a true age of the ship but experts are confident about their initial estimate that it dates back to the 1300s.

Wouldn't tree rings just tell them the age of the tree when it was cut down? Do they have another tree that's firmly dated by some other means, to which they could compare this one? I think I'm missing something!

[Junior]

Based on tree ring data collected over decades all over the world, experts can pinpoint specific years in a tree's life with amazing precision. From this data they can tell what year the tree was cut down.

[Oztrich Boy]

Do they have another tree that's firmly dated by some other means, to which they could compare this one?

pretty much
Dendrochronolgy: by matching the tree ring pattern beween two pieces of wood you can find if there was an overlap in growing periods. And you can start with living trees and develop a continous sequence over various samples back into the past.

As the sequence for European Oak now runs back 10,000 years the chances are pretty certain of matching this tree to a specific time.

[Sacajaweau]

You're right. I always laugh when they tell me a rock with writing on it is of a known age. Why????? Cause I did my "rock thing" in 1988......except the rock says 1788 with the initials of the "squatter" who became the landowner. Masons tools are cool!!