Patent ID: 6872107

Claim:
A hull structure for a boat, said hull having a bottom, a bow, a stern, and a keel extending at least partially from said bow to said stern along said bottom, a propeller shaft extending from the interior of said hill through said bottom and toward said stern from between said bow and said stern and a propeller mounted for rotation with said propeller shaft, said hull structure comprising: a) a tunnel along said bottom of said hull, said tunnel having a first portion presenting a truncated partial cylindrical cone shaped hollow surface indentation along a first portion of said bottom of said hull and a second portion presenting a constant radius extension from said first portion, said cone having a central axis and a cone angle with respect to said central axis, the smaller forward end of said cone extending toward said bow and the larger trailing end of said cone terminating at the location of said propeller within said tunnel and extending toward said stern, said second portion being connected to said first portion at said larger trailing end; b) said end of said cone at its forward end being truncated with an end closure and connected to said hull bottom to provide a substantially normal connection between said truncated end and the axis of said propeller shaft extending through said end closure and boat bottom and into said tunnel, c) the cone angle of said cone being constant from said connected truncated end toward said larger trailing end to said connection with said second portion extension; d) said cone being attached to said bottom along its exterior surfaces extending toward said stern and ending in attachment of said larger trailing end to said extension, said extension being attached to said bottom along its exterior surface extending toward said stern and ending in attachment to said stern to establish said hollow tunnel.