Marine insurance whereby the reinsurer receives all of the cedant’s interest up to a predetermined amount. For example, if an underwriter accepts £100,000 on a vessel and reinsures £50,000 on a first interest basis, any amount ‘closed’ up to £50,000 will be ceded to the reinsurer. If only £80,000 is closed to the underwriter it is his share of the risk that goes down as the reinsurer’s line holds good in the sum of £50,000.