Under the IOR became apparent that weight in ends of those pinchy-ended boats was devastating to boatspeed. With plywood as the interior material necessity, it became important remove all joinery components not required by the rules. Now the Grand Prix class is racing under the IMS rule. This rule has given us healthy hull forms, stiff and fast on all points of sail. The hulls, unlike the mutant IOR shapes, have few genetic flaws.
Plywood is history.
The newest IMS boats might have a small strip plywood where the Let's just say that the performance cruiser version is a slightly cruiser Bright Star . It's getting silly. The speed penalty for a complete interior is now reduced to a point where the dual-purpose boat can be competitive in almost all fleets. This boat is very similar to Bright Star , the Key West Race Week winner. No, dear reader, it is not me applying those labels.