How important is bridgedeck clearance?
Melvin: It all depends on how you plan to use the boat. Bridgedeck clearance is not as critical on smaller coastal-cruising cats that don’t go too far out into the big bad ocean, but on offshore boats that will be subjected to big seas, higher bridgedeck clearance is essential to minimize pounding. We look for bridgedeck clearances on cruising catamarans to be between 4 percent and 6 percent of the length of the boat off the water. This height simply makes it easier for waves to pass harmlessly between the hulls rather than pounding up underneath the bridgedeck. As well as having suitable bridgedeck clearance, a cat should have underbody surfaces that are relatively smooth. Slater: All cats will pound from time to time, especially in steep chop. The critical design factors to consider to reduce bridgedeck slamming are bridgedeck clearance, rig weight and height, bow shape, and keeping the weight out of the ends of the boat. The combination of these factors in correct balance will give
