Construction Materials 



The flotation material for floating 

 platforms and buoys generally consists 

 of polystyrene, ployurethane or hollow 

 steel, aluminum, fiberglass, or concrete 

 structures. The most popular type of 

 floats are polystyrene and polyurethane 

 foam. They should be coated with a pre- 

 servative to prevent deterioration and 

 attachment of marine flora and fauna. 

 The coating may consist of poly vinyl- 

 acetate emulsion or dense polyurethane 

 (for polystyrene), fiberglass and resin 

 (for polyurethane), plaster, or concrete 

 (Dunham and Finn 1974). When using 

 polyurethane, the monocellular type 

 should be used, as it is the only type 

 that is nonabsorbent. Extruded polysty- 

 rene (Styrofoam) is totally impermeable 

 by water and may be preferred over 

 expanded-pellet polystyrene (bead- 

 board), which is more susceptible to 

 water penetration (Dunham and Finn 

 1974). Polyurethane is naturally hydro- 

 carbon-resistant. Polystyrene can be 

 made hydrocarbon resistant. This is an 

 important factor to consider when locat- 

 ing structures in an area susceptible to 

 petroleum products. In the past, hollow 

 floats or fiberglass or metal were used. 

 Hollow-shell floats are more susceptible 

 to leakage and are being replaced by 

 shells filled with foam. Wood flotation 

 devices are used in some areas of the 

 country, such as the Pacific Northwest. 

 Platform decks may be constructed from 

 wood, concrete and plastic materials. 

 Anchor systems may be made from rope, 

 cable, or chain. Anchors can be patent- 

 ed anchors of steel or can be made of 

 concrete blocks and various makeshift 

 things, such as junk auto parts. 



Expected Life Span 



The life span of buoys and floating 

 platforms was not addressed in the lit- 

 erature. Materials treated against ma- 

 rine growth and corrosion will last long- 

 er than untreated materials. The sever- 

 ity of environmental conditions where 

 they are utilized will greatly affect 

 their longevity. 



Summary of Physical and Biological 

 I mpacts 



Construction effects. The effect 



of the installation of buoys and float- 

 ing platforms is minimal. 



Chronic effects . Shaded areas caus- 

 ed by floating structures and the areas 

 occupied by their anchors are usually 

 small and generally would not be expect- 

 ed to result in measurable effects. 

 Shading from platform decking may result 

 in a small decrease in primary produc- 

 tivity. The impact is dependent on the 

 size of the structure. Buoys and plat- 

 forms provide habitat for sessile organ- 

 isms and cover for fish. Pelagic game 

 fish are attracted to buoys and floats. 

 They are, therefore, popular sport fish- 

 ing spots. 



Cumulative effects . Cumulative 



effects were not considered in the lit- 

 erature. It is apparent, however, that 

 there can be aesthetic and navigational 

 problems created if the number of float- 

 ing objects is allowed to proliferate. 



Structural and Non-Structural 

 Alternatives 



One alternative to buoys used for 

 navigation aids or markers would be pile 

 structures. Mooring buoys could be re- 

 placed by fixed structures such as dol- 

 phins or piers. The necessity for buoys 

 could be eliminated by installing a 

 launching ramp and requiring land stor- 

 age of the boats. 



Regional Considerations 



Most of the information in the lit- 

 erature is applicable to all of the 

 coastal reqions of the United States. 

 The Buffalo District of the U.S. Army 

 Corps of Engineers (undated a) (Coastal 

 Region 8) proposed that general permits 

 be issued for navigation, mooring, and 

 special purpose buoys and floating plat- 

 forms in New York State. Specific re- 

 strictions for that area included limit- 

 ing a deck surface area to not more than 

 200 fr (61 rrr) and restricting platform 

 extension to no more than 100 ft (30.5 

 m) waterward from the high water line. 



HARBORS FOR SMALL CRAFT 



Definition 



A harbor is a protected water area 



91 



