BIOLOGICAL FOULING OF TRIESTE 



Fouling of the exterior of the bathyscaph within San 

 Diego Bay has been spectacular and a nuisance (fig. 18). 

 Profuse growth of Ohelia, Tubullaria, barnacles, tube- 

 forming worms such as Spzrorbis, and even the young of 

 the giant kelp Macrocyst is have formed dense fouling 

 covers to the extent that the paint was no longer visible after 

 a few weeks. It is of interest to note the preferential 

 settling of the organisms on the white painted surface 

 rather than on the blue band. 



The first antifouling white paint, Amercoat 85 and 33, 

 was applied following the March- April 1959 overhaul of 

 the TRIESTE (fig. 19). This paint was also fouled in a 

 short time (fig. 2 0). As indicated by this photograph, the 

 exposure to high hydrostatic pressure and low temperature 

 during the bathyscaph dives had no apparent detrimental 

 effect on the living organisms; Dives 53 (to 4100 feet) and 

 55 (to 42 00 feet) applied pressures of over 1800 psi to the 

 growing organisms. 



Prior to the initiation of NEKTON I, a standard stock 

 antifouling paint, vinyl red formula 121, was substituted for 

 the white paint (fig. 21). Good antifouling characteristics 

 were noted. However, biological growth in Apra Harbor is 

 always negligible. 



Controlled tests with Laminar X-500 conducted off 

 the NEL pier indicated that this paint would be a good 

 antifouling covering for the craft. However, following 

 two months' immersion in 1961, the craft was again heavily 

 fouled and now requires weekly cleaning by divers. 



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