Did anything specific happen on the voyage of the HMS Beagle?

The main purpose of the expedition was a hydrographic survey of the coasts of the southern part of South America as a continuation of the work of previous surveys, producing charts for naval war or commerce and drawings of the hills as seen from the sea, with height measurements. In particular, the longitude of Rio de Janeiro which formed a setting out point for these surveys was in doubt due to discrepancies in measurements and an exact longitude was to be found, using calibrated chronometers and checking these through repeated astronomical observations. Continuing records of tides and meteorological conditions were also required. A lesser priority was given to surveying approaches to harbours on the Falkland Islands and, season permitting, the Galápagos Islands. Then the Beagle was to proceed to Tahiti and on to Port Jackson, Australia which were known points to verify the chronometers. An additional requirement was for a geological survey of a circular coral atoll in the Pacific Ocean including investigation of its profile and of tidal flows.