Patent ID: 7421968

Claim:
A boat that is provided with floating tubes in a multi-layer design, which is suitable for carrying a few persons to travel on designated water surface, comprising a hull, which floats on the water surface by contacting the water and is used to carry the aforementioned persons; and a plurality of floating tube devices, which are connected orderly and are installed at a left and a right side of the hull, with each floating tube device being provided with an air bag which is filled with air, a buffer which encloses at an outer periphery of the air bag, and a surface layer unit which encloses at an outer periphery of the buffer; the buffer providing a holding space for emplacing the air bag, and an assembling slot hole which is radially connected with the holding space; the surface layer unit being provided with a sealing element which corresponds to the assembling slot hole and is used to seal that assembling slot hole again, wherein the air bag is provided with a flexible bag body forming a circular cross section when inflated and a nozzle which is connected with the bag body and adjusts air that enters into the bag body, the nozzle being located at an interior end of the assembling slot hole.