PERSPECTIVE - NEUSTON SAMPLER 



swivel 



Figure 1.— Neuston sampler with net cod-end attached. 



Net Attachment 



We replaced the grommet and bolt-through net 

 fastening system of the S-J sampler with an alu- 

 minum channel clamp (Fig. 2). Net slippage is pre- 

 vented by sewing a 1/4" rope into the net collar. 

 Stainless steel bolts remain permanently attached 

 to the sampler body so that, to mount or replace the 

 net, it is merely slid over the box and the channel 

 placed over the bolts and secured. One man can 

 replace the net in 5 min. 



Lateral Wings 



Individual fins bolt directly to the sides of the body 

 and are made of 1/8" aluminum with the inside edge 

 bent at 90° for an attachment face (Fig. 3). The 

 outer edge is bent downward 15° to stiffen it and 

 to reduce side slippage under tow. The wings 

 pivot on a bolt anteriorly and are adjusted through 

 a series of holes in the sampler body (Figs. 1, 

 2). 



Depressor 



Bolted directly to the body and adjusted as for the 

 wings (Figs. 1, 2), the depressor is made from 1/4" 



marine aluminum bent at right angles on either end 

 for attachment (Fig. 3). It serves also as the lower 

 towing point and stiffens the body. 



Tow Points 



The sampler is adjusted in relation to the towing 

 vessel by a stainless steel turnbuckle on the upper 

 bridle (roll aspect), and by selecting the lower tow 

 point (depressor) and upper tow point (leading top 

 corner of the body) from a series of holes (Figs. 1, 

 2, 3). The tow point fastening is a threaded U- 

 bolt, fastened on both sides of the sampler frame 

 (Fig. 3). 



Flotation 



A streamlined float constructed of fiberglassed, 

 polyurethane foam which bolts to the upper face of 

 the body (Figs. 1, 2). At neutral buoyancy the 

 sampler floats with the mouth opening just below 

 the water surface. As with the S-J sampler, vertical 

 positioning under tow is the balanced outcome of 

 downward depressor force and lift from the lateral 

 fins. These adjustments are made to maintain an 

 8-10 cm headspace of air in the sampler while under 

 tow. 



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