The present invention relates to a bottom-to-surface connection device
comprising at least one undersea pipe or riser (1, 1a-1b) capable of
including a single float (2, 2.sub.1-2.sub.7), said float being connected
at its bottom end to a junction device (8) creating a leaktight flexible
joint between the bottom end of the float (2) and said riser (1a), the
connection device being characterized in that said junction device (8) is
interposed between and secured to a bottom portion (1a) of the riser
going down to the sea bottom and a top portion of the riser passing
through said float and rising to the surface, said junction device (8)
comprising at least one first laminated abutment in the form of a body of
revolution having a plurality of elastomer layers defining surfaces of
revolution that are frustoconical in shape or ellipsoidal in section.