This paper on guano stems from research into hop cultivation in Kent. Parliamentary Papers give fascinating accounts of voyages made during the nineteenth century to obtain this ‘wonder’ fertiliser. The efforts made on behalf of the agricultural community by naval officers and seamen were an important extension of rural history, and were considered vital at the time. The paper describes the effort that went into this cooperation between agriculture and the navy, as well as its global scope, at a time when agricultural chemistry was in its infancy. Although developments in chemistry would displace the need for guano within two decades, the desire for guano was then very striking. Naval personnel underwent considerable danger and physical hardship during these explorations to bring farmers the fertilisers that they wanted, and some features of this narrative are explored here.