An artificial reef structure including thin tensile members as part of the structure. These tensile members readily accumulate marine life to create a more organic structure. The reef structure can accommodate a wide variety of ocean sensing and communication systems. Embedded lighting and electronic elements can be used to attract and monitor marine life.

An artificial reef to be anchored to the seabed comprises two or more juxtaposed conduits which are positioned in parallel with the direction of wave propagation. Both conduits include directrices. The upper conduit includes directrices which drive the flow of the wave's crest, and the lower conduit includes directrices which drive the water diverging from the apertures in the area under the wave's trough. The upper and lower conduits are hydraulically connected, each connection comprising a shut-down valve associated with a useful energy-generating unit.

A process for forming an artificial reef includes forming a form having a geometric shape, applying at least one blockout onto a surface of the form such that the blockout extends outwardly of the surface of the form, applying a sprayable concrete over the form and over a portion of the blockout, curing the sprayable concrete on the form for a period of time so that the sprayable concrete adheres to the blockout, and removing the cured sprayable concrete and the adhered blockout together from the surface of the form. The sprayable concrete is applied over the form until the depth of the sprayable concrete is approximately equal to a depth of the blockout. The blockout is a cinder block.

Artificial reef for recreational diving (1) comprising a base (2) of a slab of reinforced concrete and a vertically extending superstructure (3) made of concrete of inert lightweight materials that is ejected onto a structural frame comprising a plurality of stem members (32) around a trunk (31) implanted into the base and plastic grid items (12) suspended thereupon in a predetermined manner so as to form, following concrete ejection, a reef having a form and aesthetics corresponding to that of a natural reef, comprising blind crevices (9) and through holes (7) leading to chambers (8) and smaller or larger cavities (10, 11), constituting microhabitats and refuges for targeted benthic and benthopelagic organisms. The reef (1) is founded onto the seabed with one or more beams (30) introduced into holes (4) that pass perpendicularly through the base (2) and extend vertically along the superstructure (3). Artificial reefs (1) are organized in groups (20) defining an artificial oasis for recreational diving within a planned section (ABCD) of the seabed.

There is described a module for an underwater structure. The module comprises a plurality of walls defining a cavity configured such that at least two walls of said plurality of walls confront one another to provide respective stack support surfaces for supporting said module, said walls are substantially parallel to form complementary stack surfaces, such that one stack surface may rest on a surface and the other complementary stack surface provides a rest surface for another module. Two or more walls of said plurality of walls each comprise an aperture providing a conduit through each two or more walls to said cavity, respective apertures of said two or more walls and said cavity configured to provide a water flow path into, through and from said cavity. The water flow path may be considered unconstrained or at least substantially unconstrained in that water may flow through the apertures and cavity without deviation or interruption other than by the module or cavity walls. In stacked formation an aperture may be occluded or partially occluded but still the module when on its own may provide water pathways which may be considered unconstrained or substantially unconstrained.

A process for forming an artificial reef includes forming a form having a geometric shape, applying at least one blockout onto a surface of the form such that the blockout extends outwardly of the surface of the form, applying a sprayable concrete over the form and over a portion of the blockout, curing the sprayable concrete on the form for a period of time so that the sprayable concrete adheres to the blockout, and removing the cured sprayable concrete and the adhered blockout together from the surface of the form. The sprayable concrete is applied over the form until the depth of the sprayable concrete is approximately equal to a depth of the blockout. The blockout is a cinder block.

A process for forming an artificial reef includes forming a form having a geometric shape, applying at least one blockout onto a surface of the form such that the blockout extends outwardly of the surface of the form, applying a sprayable concrete over the form and over a portion of the blockout, curing the sprayable concrete on the form for a period of time such that the sprayable concrete adheres to the blockout, and removing the cured sprayable concrete and the blockout from the surface of the form. The blockout is of a cast concrete material such as a cinder block. The blockout has openings therein so as to open to an interior of the artificial reef.

A process for forming an artificial reef includes forming a form having a geometric shape, applying at least one blockout onto a surface of the form such that the blockout extends outwardly of the surface of the form, applying a sprayable concrete over the form and over a portion of the blockout, curing the sprayable concrete on the form for a period of time such that the sprayable concrete adheres to the blockout, and removing the cured sprayable concrete and the blockout from the surface of the form. The blockout is of a cast concrete material such as a cinder block. The blockout has openings therein so as to open to an interior of the artificial reef.

A concrete wave attenuating apparatus facilitating the formation of a vertical oyster reef includes: A) A concrete wave attenuating frame having i) a concrete frame top and a concrete frame bottom defining a periphery of the frame, each having corners and sides extending between the corners, ii) concrete corner posts extending generally vertically between generally aligned corners of the concrete frame top and the concrete fame bottom, iii) concrete sides between the concrete corner posts extending generally vertically between the generally aligned sides of the of the concrete frame top and the concrete fame bottom, a plurality of passages extending through the concrete sides; B) A space defined within the concrete wave attenuating frame, wherein the plurality of passages extend to the space; and C) optionally Cultch material within the space.