The Wreck of the Trinidad Valencera, which sank in Kinnagoe Bay, Co. Donegal in 1588, was discovered by members of the City of Derry Sub-Aqua Club in the early seventies. The wreck was within this jurisdiction and the material recovered over a few years was delivered to the Receiver of Wreck in Letterkenny. As the National Museum did not, at the time, have the facilities to conserve this material, its conservation was undertaken by the Ulster Museum. The long-term loan to the Ulster Museum was formalised in 1979.
The Ulster Museum then made a proposal to the Irish authorities to buy the material. It was decided that the Ulster Museum should pay a nominal sum of £10 on condition that it would, at the same time, also reimburse the expenses of Derry Sub-Aqua Club and on condition that the material would eventually be put on display in Derry in a suitable building.