Hull assembly for a personal watercraft

Abstract

A personal watercraft has a hull and left and right flow attachment features connected to an underside of the hull near a stern thereof. The left and right flow attachment features are disposed on opposite sides of a longitudinal centerplane of the personal watercraft and are laterally spaced therefrom. For each flow attachment feature of the left and right flow attachment features: the flow attachment feature has a flow surface facing downwardly, the flow surface having a front end and a rear end, the flow surface extending upwardly and rearwardly from the front end to the rear end; and the flow surface is curved in a longitudinal direction of the watercraft such that, in response to water flowing along the flow surface as the personal watercraft moves forwardly on the water, the stern is pulled downwards relative to a bow of the hull.

1 . A personal watercraft comprising:
 a deck;   a hull supporting the deck, the hull having a bow and a stern opposite the bow;   a left flow attachment feature and a right flow attachment feature connected to an underside of the hull near the stern, the left and right flow attachment features being disposed on opposite sides of a longitudinal centerplane of the personal watercraft, the left and right flow attachment features being laterally spaced from the longitudinal centerplane, for each flow attachment feature of the left and right flow attachment features:   the flow attachment feature comprises a flow surface facing downwardly, the flow surface having a front end and a rear end, the flow surface extending upwardly and rearwardly from the front end to the rear end;   the flow surface is curved in a longitudinal direction of the watercraft such that, in response to water flowing along the flow surface as the personal watercraft moves forwardly on the water, the stern is pulled downwards relative to the bow.   
     
     
         2 . The personal watercraft of  claim 1 , wherein the flow surface is curved in a lateral direction of the watercraft. 
     
     
         3 . The personal watercraft of  claim 1 , wherein, for each flow attachment feature of the left and right flow attachment features:
 in a cross-section of the watercraft taken along a plane parallel to the longitudinal centerplane and traversing the flow attachment feature, the flow surface has a radius of curvature;   a length of the flow surface is measured between the front and rear ends; and   a ratio of the length of the flow surface over the radius of curvature of the flow surface is between 0.3 and 0.7.   
     
     
         4 . The personal watercraft of  claim 3 , wherein, for each flow attachment feature of the left and right flow attachment features:
 the radius of curvature is a first radius of curvature;   the plane is a first plane;   the flow surface is curved in a lateral direction of the watercraft;   the flow surface extends upwardly and laterally outwardly from an inner lateral end to an outer lateral end of the flow surface, a width of the flow surface being measured between the inner and outer lateral ends; and   in a cross-section of the watercraft taken along a second plane normal to the longitudinal centerplane, extending vertically and traversing the flow attachment feature, the flow surface has a second radius of curvature;   a ratio of the width of the flow surface over the second radius of curvature of the flow surface is between 0.8 and 1.2.   
     
     
         5 . The personal watercraft of  claim 1 , wherein the left and right flow attachment features are distinct from the hull and are fastened to the hull. 
     
     
         6 . The personal watercraft of  claim 5 , wherein:
 the hull has left and right downward-facing surfaces near the stern; and   the left flow attachment feature and the right flow attachment feature are fastened to the left and right downward-facing surfaces respectively.   
     
     
         7 . The personal watercraft of  claim 5 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature, the flow surface thereof defines at least one opening for inserting a fastener through the flow attachment feature to secure the flow attachment feature to the hull. 
     
     
         8 . The personal watercraft of  claim 1 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature:
 in a cross-section of the watercraft taken along a plane parallel to the longitudinal centerplane and traversing the flow attachment feature, the flow surface has a radius of curvature that is greater than 40 mm.   
     
     
         9 . The personal watercraft of  claim 1 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature:
 in a cross-section of the watercraft taken along a plane parallel to the longitudinal centerplane and traversing the flow attachment feature, the flow surface has an arc length that is less than 45°.   
     
     
         10 . The personal watercraft of  claim 1 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature, the rear end of the flow surface is disposed forward of a transom of the stern or is longitudinally aligned with the transom of the stern. 
     
     
         11 . The personal watercraft of  claim 1 , wherein:
 the watercraft further comprises a left sponson and a right sponson disposed on opposite sides of the longitudinal centerplane: and   for each flow attachment feature of the left and right flow attachment features, at least a majority of the flow surface of the flow attachment feature is disposed vertically lower than the left and right sponsons.   
     
     
         12 . The personal watercraft of  claim 11 , wherein:
 each sponson of the left and right sponsons is adjustable between a raised position and a lowered position; and   for each flow attachment feature of the left and right flow attachment features, at least a majority of the flow surface of the flow attachment feature is disposed vertically lower than the left and right sponsons in the lowered positions thereof.   
     
     
         13 . The personal watercraft of  claim 1 , wherein:
 the hull has a left corner surface and a right corner surface, the left corner surface being disposed adjacent to and forwardly of the left flow attachment feature, the right corner surface being disposed adjacent to and forwardly of the right flow attachment feature;   the front end of the left flow attachment feature is disposed vertically higher than a lower end of the left corner surface such that a left step is defined between the left corner surface and the front end of the left flow attachment feature; and   the front end of the right flow attachment feature is disposed vertically higher than a lower end of the right corner surface such that a right step is defined between the right corner surface and the front end of the right flow attachment feature.   
     
     
         14 . A hull assembly for a personal watercraft, comprising:
 a hull having a bow and a stern opposite the bow;   a left flow attachment feature and a right flow attachment feature connected to an underside of the hull near the stern, the left and right flow attachment features being disposed on opposite sides of a longitudinal centerplane of the hull, the left and right flow attachment features being laterally spaced from the longitudinal centerplane, for each flow attachment feature of the left and right flow attachment features:   the flow attachment feature comprises a flow surface facing downwardly, the flow surface having a front end and a rear end, the flow surface extending upwardly and rearwardly from the front end to the rear end; and   the flow surface is curved in a longitudinal direction of the hull such that, in response to water flowing along the flow surface as the personal watercraft moves forwardly on the water, the stern is pulled downwards relative to the bow.   
     
     
         15 . The hull assembly of  claim 14 , wherein the flow surface is curved in a lateral direction of the hull. 
     
     
         16 .- 20 . (canceled) 
     
     
         21 . The hull assembly of  claim 14 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature:
 in a cross-section of the hull assembly taken along a plane parallel to the longitudinal centerplane and traversing the flow attachment feature, the flow surface has a radius of curvature that is greater than 40 mm.   
     
     
         22 . The hull assembly of  claim 14 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature:
 in a cross-section of the hull assembly taken along a plane parallel to the longitudinal centerplane and traversing the flow attachment feature, the flow surface has an arc length that is less than 45°.   
     
     
         23 . The personal watercraft of  claim 14 , wherein, for each flow attachment feature of the left flow attachment feature and the right flow attachment feature, the rear end of the flow surface is disposed forward of a transom of the stern or is longitudinally aligned with the transom of the stern. 
     
     
         24 . The hull assembly of  claim 14 , wherein:
 the hull assembly further comprises a left sponson and a right sponson disposed on opposite sides of the longitudinal centerplane; and   for each flow attachment feature of the left and right flow attachment features, at least a majority of the flow surface of the flow attachment feature is disposed vertically lower than the left and right sponsons.   
     
     
         25 . (canceled) 
     
     
         26 . The hull assembly of  claim 14 , wherein:
 the hull has a left corner surface and a right corner surface, the left corner surface being disposed adjacent to and forwardly of the left flow attachment feature, the right corner surface being disposed adjacent to and forwardly of the right flow attachment feature; and   the front end of the left flow attachment feature is disposed vertically higher than a lower end of the left corner surface such that a left step is defined between the left corner surface and the front end of the left flow attachment feature; and   the front end of the right flow attachment feature is disposed vertically higher than a lower end of the right corner surface such that a right step is defined between the right corner surface and the front end of the right flow attachment feature.