In 1865–66, having been given a health sabbatical by his church, he traveled to San Francisco via the Straits of Magellan on the ironclad monitor with Commodore John Rodgers (a parishioner of his), with international goodwill stops along the way. Officially, he was designated Commodore's Secretary, but was considered "acting chaplain", giving services on board and even conducting a shipboard wedding for a German American they encountered in Montevideo, an incident Bush recounted in dispatches he wrote for "The Overland Monthly". Coincidentally, the fleet observed the punitive shelling of a defenseless Valparaíso, Chile by the Spanish Navy during the Chincha Islands War, after mediation efforts by Rodgers failed.