| 0 "Segregate the core from all openings": Any opening cut into or through the core can and will be a potential source of exposure to water. This applies to all core materials, foam and balsa. This is specially critical with fittings mounted on the hull bottom and all openings cut through the laminate including vents, ports, hatches,.. The core can be phased out by the use of fillets and the opening cut or drilled through built up single skin laminate. A solid high density insert can be introduced into the laminate, replacing the core in the area where the hole or opening is to be cut. Main resistances a sandwich core must have: • As greater the Shear Resistance be, better the flexion performance the sandwich core would have • Shear elongation: A rigid material is easy to broke, but a thermoplastic material have a permanent deformation. STRUCT-C0RE (cross linked material) it recovers the original form without breaking itself after the pressure. • Is also a resilient material, it could absorb highly the impact energy without be broken. • Fatigue strength: elongation in STRUCT-C0RE avoid critical points of pressure concentrated and gives to the core a high fatigue strength |