Water jet propulsion boat and boat

Abstract

A water jet propulsion boat includes a boat body and first and second sponsons on a first side of a rear portion of the boat body. A lower surface of the second sponson is higher than a lower surface of the first sponson, and a rear end of the second sponson is rearward of a rear end of the first sponson.

What is claimed is: 
     
         1 . A water jet propulsion boat comprising:
 a boat body;   a first sponson provided on a first side of a rear portion of the boat body; and   a second sponson provided on the first side of a rear portion of the boat body; wherein   a lower surface of the second sponson is higher than a lower surface of the first sponson; and   a rear end of the second sponson is rearward of a rear end of the first sponson.   
     
     
         2 . The water jet propulsion boat according to  claim 1 , wherein
 the lower surface of the first sponson is located so to be below a waterline of the water jet propulsion boat when the water jet propulsion boat is travelling straight; and   the lower surface of the second sponson is located so to be above the waterline of the water jet propulsion boat when the water jet propulsion boat is travelling straight.   
     
     
         3 . The water jet propulsion boat according to  claim 1 , wherein a front end of the second sponson is forward of the rear end of the first sponson. 
     
     
         4 . The water jet propulsion boat according to  claim 1 , wherein an outward end of the second sponson farthest outward from the boat body is at a same location as an outward end of the first sponson farthest outward from the boat body in a left-right direction. 
     
     
         5 . The water jet propulsion boat according to  claim 1 , wherein an outward end of the second sponson farthest outward from the boat body is farther from a centerline of the boat body than an outward end of the first sponson farthest outward from the boat body in a left-right direction. 
     
     
         6 . The water jet propulsion boat according to  claim 1 , wherein the first sponson is oriented such that the front end and the rear end are aligned horizontally, or the front end is higher than the rear end. 
     
     
         7 . The water jet propulsion boat according to  claim 1 , wherein the second sponson is oriented such that a front end and the rear end are aligned horizontally, or the front end is higher than the rear end. 
     
     
         8 . The water jet propulsion boat according to  claim 1 , wherein the first sponson and the second sponson are parallel or substantially parallel to each other when viewed in a left-right direction. 
     
     
         9 . The water jet propulsion boat according to  claim 1 , wherein the first sponson and the second sponson are not parallel to each other when viewed in a left-right direction. 
     
     
         10 . The water jet propulsion boat according to  claim 1 , wherein the rear end of the first sponson and the rear end of the second sponson are forward of a transom positioned at a rear end of the boat body. 
     
     
         11 . A boat comprising:
 a boat body;   a first sponson on a first side of a rear portion of the boat body; and   a second sponson on the first side of the rear portion of the boat body; wherein   a lower surface of the second sponson is higher than a lower surface of the first sponson; and   a rear end of the second sponson is rearward of a rear end of the first sponson.