This is from the FB Design website
Differentiated sandwich laminate
Description: It concerns a differentiated sandwich laminate (comprising an outer layer, an intermediate layer or “centre”, and an inner layer), in which the resin used for making the outer layer is different from, and incompatible with, the resin used for making the inner layer.
The inner layer and outer layer of sandwich laminate of the adjacent layers of two different sandwich laminates, made according to the invention, are made to adhere in a watertight manner to each other using mechanical-assembly means.
The resin used for external lamination protects from osmosis and avoids the absorption of water. The internal lamination gives higher protection against shock loading. The presence of a core between the two laminats has an effect of separation. The internal laminat reacts as a second hull and guarantees the floatability in case of damage of modest proportion.
But then it was an Italian!
Cost is just under a million pounds each. Dont know about range. But when they left harbour, after a few minutes and miles warming up, they sudenly turned, put on an incredible speed and disappeared down The Swinge.