A smooth bore, self-aligning connection for pipes of the type used in hydraulic dredging. In this connection, the spigot end of one pipe contacts metal to metal at the bell end of the other pipe. A packing gland is defined outwardly of the contacting pipe ends by a positioning ring toe and an annular ring of the bell. A third annular ring on the bell end engages a stepped ring on the spigot end to align the pipes longitudinally as well as radially. A locking ring which is threadedly adjustable engages a skirt depending from a fourth annular ring formed on the bell to lock the spigot end of the pipe to the bell end. The bell and spigot connection of this invention is also adaptable to a pontoon pipe having a flexible reinforced rubber hose section between the spigot and bell ends of a pipe.