Investigations showed that HMAS HOBART, (cruiser), was only one of a number of ships attacked in error, by US 7th Air Force fighters, on 16 and 17 June. PCF 19, a US patrol boat, was sunk with the loss of five lives on 16 June. On 17 June US ships BOSTON, EDSON, POINT DUME, and PCF 12, were attacked. Unusual atmospheric conditions prevailing in Vietnamese waters at this period have been commented on by senior US Air Force officers.