Algunos datos sobre la profundidad que alcanza el arte de cerco en la pesqueria atunera tropical

The fishing gear is, together with the fishing vessel, one of the essential elements of the fishing activity. In the case of purse seine, the length and size of the net plays an important part in fishing efficiency. This paper tries to establish some relationships between the physical characteristics of the purse seine net and the effective depth which it reaches, by placing a depth meter on the net, close to the netting, which registered the depth of the net during each of the 32 trips carried out in the Atlantic and Indian Oceans. The data obtained, from two different vessels, show that the maximum depths reached by the net were 74% and 67% of the draft of the vessels, which were 220 and 272 m, respectively. The maximum speed of the descent of the net was attained, in most cases, in the first two minutes after the start of the operation.