He needs to learn more about shipbuilding and maritime commerce in the age of sail. A very few ships lasted as long as twenty years. Those that were built quickly, with green wood, had the shortest life spans. Merchant ships were much shorter lived than naval vessels because they used cheaper materials, spent less building a tight ship, and did less maintenance than did the navy. A merchant ship was expected to recoup the investment of purchase within three to five years. Many did not last that long.
That's interesting. Do you have a place I can go to read more about that? I would've thought that shipwrights generally would not have used green wood and would have known better. They spent so very much time and effort building a ship, with only hand tools... It would surprise me that they only expected the ship to last a few short years. Given the craftsmanship I've seen in the ones that -did- survive it would be surprising to think that they expected all that attention to detail to possibly be wasted.