Abstract: The present invention deals with flexible wall dams used for restricting the flow of rivers, seawaters, or the like, using in combination: an upstanding, continuous, impermeable, inextensible, reinforced, flexible wall having elongated upper and lower peripheral edges, with the lower edge positively and substantially sealingly secured to the base of the waterbed by being inserted into a curvaceous longitudinal channel anchored to the waterbed, and the upper edge supported by means of floating vessels, transferring their loads through anchoring cables to points upstream.

Abstract: A system for aligning and securing the end of a subsea flowline to a subsea wellhead and guide base system associated with an oil or gas completion system which provides for the manipulation of the centerline of pins on the subsea flowline end connection attachment, the centerline of receptacles on the flowline receiving structure, and a centerline on pulling tool guidance means to a concurrent location such that the pins can engage the receptacles and thereby the flowline end can be positively locked into the flowline receiving structure at varying vertical rotational positions of the end of the flowline and subsequently when a desired vertical rotational position or elevation of the flowlines is achieved other pins will engage other receptacles and lock the flowline end attachment and therefore the flowlines against further vertical movement.