Most major production boat builders claim "hand-laid fiberglass" or "hand-laid fiberglass construction" in their brochures. In fact however, most use chopper guns to replace the traditional fiberglass mats by "chopped strand," a mixture of glass fibers only up to 2 inches long, that are wetted with resin by the "chopper gun," and sprayed into the mold. Only the woven rovings are rolled or "laid in" by hand.

So what’s wrong with this? A 100% hand-laid hull of the same thickness has about three times the impact strength versus the production boat hull. Because of price reasons the hull of typical production boats are only built with just enough thickness to withstand normal use; you better not dare to go through serious weather, run onto a submerged log, not to mention submerged rocks.
 

The hull of the Vilm is not only 100% hand-laid, with no "chopped strand," but is also thicker than the hulls of most production boats similar in size.

In addition, the boat has a heavy built, very strong inner liner laminated into the lower portion of the hull; the bulkheads are thoroughly laminated into place from both sides as are the other parts of the interior, instead of just being held into place by small metal brackets and screws as is the case in production boats.

Summary:
The impact and tear strength of a Vilm hull, is up to ten times higher than that of production boats. This is the difference between a serious, seaworthy cruising boat and a production "pleasure boat." This also is the reason for the very high resale value of a Vilm which will still cruise safely in rough seas when a production boat is already in recycling.