He spent several months studying the history of the region and learning Spanish, embarked in HMS Belvidera for the West Indies in January 1834[6] and arrived in British Honduras in May 1834.

General Juan José Flores, ex-President of Ecuador, arrived in Costa Rica in mid-1848; he had visited London in 1845–46 and met prominent people including Lord Aberdeen, Palmerston's predecessor as Foreign Secretary.

Now he wrote to Palmerston proposing a British protectorate over Costa Rica, and he persuaded President José María Castro to make the same request via his envoy in London.

Advised by Chatfield, in June 1847 Lord Palmerston defined the borders of the Miskito Kingdom, from Cape Honduras in the north, to the San Juan River in the south.

United States interests also wanted to establish an inter-ocean canal, and in 1849 Chatfield and his American rival, Ephraim Squier, engaged in a diplomatic duel for regional supremacy.

But Chatfield had over-reached himself and Palmerston repudiated his action as part of negotiations for the Clayton–Bulwer Treaty which resolved issues in Central America between Britain and the United States.