The parties had entered into an agreement for a drilling rig to be towed from Louisiana to Italy, which included a clause stating that disputes would be settled by a court in England.

After the lower courts refused to uphold the forum selection clause, the Supreme Court held that it was enforceable unless the party seeking to avoid it could meet the high burden of showing it to be unreasonable or unjust.

In the light of present-day commercial realities and expanding international trade, [the Supreme Court] conclude[d] that the forum clause should control absent a strong showing that it should be set aside.

Although their opinions are not altogether explicit, it seems reasonably clear that the District Court and the Court of Appeals placed the burden on Unterweser to show that London would be a more convenient forum than Tampa, although the contract expressly resolved that issue.

The correct approach would have been to enforce the forum clause specifically unless Zapata could clearly show that enforcement would be unreasonable and unjust, or that the clause was invalid for such reasons as fraud or overreaching.