The Swedish coastline is in most places much indented and surrounded by a fringe of islets (“skerries”), rocks and islands generally known as our archipelago, or “skaergaard” (literally “skerry-garden”), through which visiting ships must navigate to reach Swedish ports. Depths in the channels between these islands are very varied, and since the areas are vast, the task of collecting data and incorporating them into charts is immense. The Swedish State does indeed chart these areas, but many parts of the charts are old, and before the Tsesis decision (N.J.A. 1983, p. 3) there was never any question of the State being liable for inaccuracies in the charts. There have been, however, cases of liability for misplaced sea marks, and for misleading depth announcements in confined areas, such as ports, canals, docks and their approaches.

Sweden, being much concerned about pollution of her long and beautiful coastline, has of course signed and ratified the 1969 Civil Liability Convention as well as the 1971 Fund Convention, the combined effect of which is to channel liability for ships’ pollution of the sea to the shipowner and eventually to the oil industry, through imposition of strict liability on the shipowner. But at the Convention conferences certain States were against strict liability, and the final solution was a compromise proposed by the British delegation, involving certain exceptions from the strict liability. One of these was for damage proved to be “wholly caused by the negligence or other wrongful act of any Government or other authority responsible for the maintenance of lights or other navigational aids in the exercise of that function”. The Convention has been introduced into Swedish legislation by being transformed into a Swedish Act known as the 1973 Oil Liability Act (1973: 1198). Here the exception takes the form—in reasonably accurate translation—that the shipowner shall be free from liability where he shows that the damage “was wholly caused by the fault or neglect of any Swedish or foreign authority in the fulfilment of a duty to maintain lights or other aids of navigation”.

In October 1977 the Soviet tanker Tsesis, with a draught of just over 8.5 metres, under pilotage northward in the Landsort-Södertälje fairway, hit a submerged rock not marked on the chart. The rock ripped open a length of the ship’s bottom, causing considerable oil leakage and pollution of nearby waters. The Swedish State sued the Soviet shipowners for compensation for oil damage and cleaning costs and indemnity for salvage incurred because of the Soviets’ refusal to employ any but Soviet salvors, while the Soviets sued the Swedish State for ship damage and indemnity for any salvage they might be adjudged liable to pay.