61. A person shall not have on board any boat used for fishing for salmon in the sea—
(a)any drift net of greater length than 1,375 metres;
(b)any number of drift nets joined together in such a way that their total length is greater than 1,375 metres;
(c)any number of drift nets which, if they were joined together, would have a total length greater than 1,375 metres;
(d)any drift net or part thereof containing more than 45 full meshes measured vertically between the top rope and the bottom rope of the net.