Take a look at the latest J model, a 29-foot-long boat called the J/88 (that's 8.8 meters). It was announced in February ("J/Boats Will Launch New J/88 in 2013") and should get wet by late June, so it's coming together fast. These photos show the two biggest parts of the boat, the hull and the deck.
This is what a hull looks like as it's released from a two-part mold, faired to perfection so it produces a fiberglass part that's a perfectly shiny, smooth hull. If we could see inside the boat, we probably wouldn't see much; at this point the hull is a shell made with resin-infused E-Glass and a balsa core.
The second photo shows what's called the deck plug, which looks very much like a sailboat cockpit with sidedecks, a couple of seats, cut-outs for winches, and foot braces in the cockpit sole. The plug is the mold with which the production mold is built. Once the plug is shaped just the way designer Rod Johnstone wants it, a mold will be built on top of it, which can then produce identical decks made with Corecell and resin-infused E-glass. The finished product will look very much like this photo, only it'll probably be white.
There's quite a bit more to finishing the boat, including bonding the hull and deck together, but these are certainly the big pieces, and looking at them takes me back to the year that J/Boats launched its last 29-footer, the J/29. That boat looked a lot like the original J/Boat, the J/24, and was 11 feet wide compared to the J/88, which is 9 feet, 6 inches. The J/29 was very fast in its day, but something tells me the 88's narrower hull, which is more than 1,000 pounds lighter, fitted with an up-to-date bulb keel, will make this one much faster. Rod Johnstone designed quick boats right from the start, but in the intervening 32 years, he's never stopped trying to make them quicker.