Luhrs Marine Group Hunter Marine Corporation Yacht Builders Luhrs and Hunter Marine build plastic sailboats that shatter in heat or cold. Millville New Jersey

I have a small 17 ft Hunter sailboat. Hunter and its owner Luhrs Marine manfacture sailboats worth a few thousand dollars to several hundred thousands of dollars.

Last winter my boat mysteriously developed severe cracks in its hull.  Some of the cracks are 1/4 inch thick and 10 feet long. The hull now has no structural integrity and is completely useless to me. It seems their Advanced Composite Process hulls can't withstand extreme temperature changes. Even their owners manual tells you not to cover the boat with a dark boat cover - I guess they know the heat from the sun might crack their hulls.

I've done some investigating and found that the product they use (BASF Luran S) has a coefficient of thermal expansion that is far inferior to other common boat building materials. Morover, it appears that this website has had dozens of Hunter owners who have experienced the same problem.

Here are some photos of the cracks that mysteriously appeared one morning.

http://picasaweb.google.com/p.eisens...CL3Zp-H_tP-cAw#