Hull Design Defects

Here's a good example of poor design and construction detail.  
Utilizing a glass over plywood framing system, there are no fillets under the frames or stringers which are butted hard against the hull.  

This creates hardspots with the propensity for stress cracking. 
In addition, the length-to-height ratio of the tall stringers creates instability where the stringers are likely to buckle under impact loading. Additional framing between the stringers is needed to stabilize them. Also note that there are only two hull side stiffeners so that flexing of the sides is likely to cause hull/deck joint breakage. In the forward section, a dog leg in the stringer profile can be seen.  

In this case, the 3/4" plywood was fractured in three places.  

This is another good example of the structural integrity of a bulkhead being defeated by cutting it full of holes.
It is perforated like a postage stamp and is destined to fail.

Properly designed by the designer, the builder apparently saw nothing wrong with drilling the frames full of holes. 

Note that the width of the top hats are about the same as the width of the bottom panel spans. 

Yacht: 56' Magnum, 2600 HP. With this kind of horsepower, the mounting system and shafts will not tolerate movement.