Sweden and the USSR agreed maritime boundary in the Baltic in 1988 and, subsequently, in 1989 Poland and Sweden agreed on the maritime boundary using the terminus agreed in the Sweden and the USSR agreement. In the negotiations on the delimitation of the continental shelf and the fisheries zone, Poland and Sweden disagreed on the effect to be given to the Swedish island of Gotland. Poland objected to the position of Sweden that Gotland should be allowed full effect and argued for disregard of the island.
The position of Poland on the effect of Gotland appears to have been affected by two facts: first, the Soviet Union was also in dispute over the effect of Gotland with Sweden and thus it seemed better to wait and see the result of the negotiations between the USSR and Sweden; and second, if Poland had recognized the effect of Gotland, then it might have weakened its position vis-à-vis Denmark which argued for the full effect to the Danish island of Bornholm.
The disputed area covered some 500 km2. This area remained a white zone until 1989 when they agreed on a boundary of the continental shelf and the fisheries zone one year after the USSR and Sweden concluded their maritime boundaries in 1988. They agreed to give 75 per cent effect to Gotland, which was treated in the same way as between Sweden and the Soviet Union in 1988.
An median line-equidistance-based maritime boundary between Sweden and Poland would extend generally from a Denmark-Poland-Sweden tripoint to Russia-Poland-Sweden. The agreement between the Government of the Kingdom of Sweden, the Government of the Polish People’s Republic and the Government of the USSR concerning the Common Delimitation Point of their Maritime Boundaries in the Baltic Sea several key tripoints in the Baltic have been finalised through agreements between Poland, Sweden and the USSR (1989), Estonia, Latvia and Sweden (1997) and Estonia, Finland and Sweden (2001). The tripoint between Poland, Sweden and the former USSR, was signed on the very day that the last bilateral agreement, i.e. the one between Poland and Sweden, entered into force.
in concluding a delimitation giving full weight to Bornholm, Denmark and Sweden apparently felt that this ‘would strengthen the Danish position vis-à-vis the GDR [German Democratic Republic] and Poland and the Swedish position in support of full effect for Gotland vis-à-vis Poland and the USSR’. Nevertheless, Bornholm is a relatively large (588 km2) island with a population of around 44,000, and is thus no inconsequential islet that could be readily discounted.