Chafing gear may be used or possessed but shall not be connected directly to the terminal, or closed, end of the cod-end. Except for chafing gear prescribed under federal groundfish regulations adopted pursuant to the Magnuson Fishery Conservation and Management Act (16 U.S.C., Sec. 1801 et seq.), all chafing gear shall have a minimum mesh size of six inches, unless only the bottom one-half, or underside, of the cod-end is covered by chafing gear, which may be of any size mesh.