121.—(1) For the purpose of the calculation of earnings-related contributions payable in respect of earnings paid to or for the benefit of a person in respect of that person’s employment as a mariner—
(a)regulation 12(1) shall apply, save that in the case of a contribution payable on earnings above the upper earnings limit or the prescribed equivalent of that limit, the appropriate contributions calculator prepared by the Board may be applied;
(b)in the alternative, paragraphs (2), (3) or (4) and (5) of that regulation shall, except in relation to secondary Class 1 contributions payable at a rate reduced in accordance with regulation 119, apply in respect of those earnings.
(2) Subject to paragraphs (3), (4) and (5) of regulation 12 where the secondary Class 1 contribution is payable at a rate reduced in accordance with regulation 119, that contribution may be calculated in accordance with the scale prepared by the Board appropriate to that rate or, in the case of such a contribution payable on earnings above the upper limit or the prescribed equivalent of that limit, a contributions calculator appropriate to that rate, prepared by the Board.