Submersible observation vessel

A hull comprising:

• (a) a forward seal including a circular band having an inwardly slanted first face clad in monel, a flat second face with an annular groove and a shoulder radially outward of said second face, said shoulder having a plurality of bores equally spaced about the circumference, a neoprene bearing gasket lining a bottom wall and inner diameter wall of said annular groove, and a neoprene external gasket adjoining an outer diameter wall of said annular groove;
• (b) a hatch hingedly mounted on said forward seal and having a generally hemispherical shaped acrylic member, a hatch ring that abuts a circumferential edge of said acrylic member, a hold-down ring that fixedly attaches to said hatch ring and secures said edge of said acrylic member in an airtight abutment with said hatch ring and a latch to hold said hatch against said forward seal;
• (c) a rear seal having a circular band having a forward face with an annular groove and a shoulder radially outward from said face, said shoulder having a plurality of bores equally spaced about the periphery, a neoprene bearing gasket lining a bottom wall and an inner diameter wall of said annular groove, and a neoprene external seal adjoining an outer diameter wall of said annular groove;
• (d) an ellipsoid bulkhead fixedly attached to and closing said rear seal;
• (e) a plurality of intermediary seals comprising a circular band having a pair of faces each with an annular groove and a shoulder radially outward of said faces, said shoulder having a plurality of bores spaced equally about the circumference, a neoprene bearing gasket lining a bottom wall and inner diameter wall of each said annular grooves, and a neoprene external seal adjoining an outer diameter wall of said annular groove;
• (f) a plurality of acrylic cylinders captured between said forward, rear, and intermediary seals, a first cylinder having peripheral edges at one end received in each said annular groove of said forward seal, contiguous with said neoprene bearing gasket along said inner diameter wall and said bottom wall of said annular groove, said neoprene external gasket snugly fit between said outer diameter wall of said annular groove and said first cylinder, said first cylinder having peripheral edges at the other end received in a first intermediary seal, a second cylinder similarly interposed between said first and a second intermediary seals, and a third cylinder similarly interposed between said second intermediary seal and said rear seal;
• (g) a tie-bar unit having a plurality of rods with threaded ends to pass through said bores of said seals, a plurality of nuts that screw on said threaded ends of said rods, and a plurality of turnbuckles that join said rods into a single unit;
• and
• (h) an integral cradle comprising a pair of laterally spaced apart and longitudinally extending side rails, a plurality of support cross members fixedly attached to said side rails and supporting each said first, second and intermediary seals, and a plurality of clips fixedly attached to said support members to prevent said seals from moving transversely of said cross members.