Floating and nonsubmersible nautical craft

Floating, nonsubmersible nautical craft comprising a partially immersed hull, intended for the accommodation of passengers, closed over all, provided at the top with means of access normally in constant communication with the atmosphere, and portholes for observation of the underwater medium,

• further comprising means of stabilization and buoyancy separate from the hull and means for varying the draft, means of propulsion and a pilot station, the hull and means of stabilization and buoyancy have a modular in transverse section, the hull being of generally tubular shape, flattened laterally, with a horizontal main axis having a succession of portholes on each of its longitudinal flanks, the means of stabilization and buoyancy having, in vertical, transverse cross section, the general form of a flat, inverted U and comprising a chest and floats respectively connected to said chests on either side thereof, said floats being movable between two extreme positions, one being low, in which floats are oriented downward, and the other high, in which floats are oriented at least substantially horizontally, characterized by the fact that each float has, in transverse cross section, the general form of a curvilinear quadrilateral limited by a rectilinear inner side an outer side opposite the inner side, two lateral sides, an inner one and an outer one with concavities turned toward one another and toward the interior of the float;
• so that in low position, the float has its inner side coplanar with the outer lower side of said chest, its outer side oriented downward and substantially at mid-height of the portholes, at the same level as the low line of flotation, and that in high position, the float has its inner side away from said chest and oriented transversely downward and toward the outside of the craft;
• its substantially vertical outer side defining the extreme longitudinal border of the craft furthest from the vertical plane of symmetry, its inner lateral side placed substantially horizontally, substantially at the level of the upper longitudinal border of the portholes.