Patent ID: 8622013
Filing Date: 2014-01-07
Classification: B63B

Abstract:
1. A step shape for a planing hull, wherein a surface immediately in front of said step makes up only part of a beam or width of a planing surface and a remainder of the beam or width of said planing surface includes a planing surface, said step shape including a portion of said planing surface, a step depth at the end region of said portion of said planing surface followed by a surface region having a contour that approximates a trajectory or wake of water which would occur directly off of said portion of said planing surface near but above a transition speed and desired attack angle, said surface region being at a depth that will cause water to contact a further surface region behind said surface region having said contour when the hull is at transition speed from a displacement mode to a planing mode, but does not contact said surface region at a planing speed faster than said transition speed, said further surface region being at such a depth to have dynamic planing lift on the said surface behind or on the said step depth when the said hull is at a transition speed from a displacement mode to a planing mode and which, at increased planing speed, principal water flow from the said step does not contact the said surface region behind the said step depth, said step being located in the back 40% of the said hull, said step further comprising a first planing surface with an end region adjacent to said planing surface with a positive second derivative shape of 0.3 to 3.0 (cm −1 ) to form an angle at the end of said end region which is less than 90°, a second region of the hull directly behind said end region with depth into the hull surface of 5±4 mm measured from a line, which starts on the said planing surface 20cm in front of said end region and is tangent to the said end region, and extending backwards up to 20 cm.