The relationships became particularly friendly when the sailors discovered that the women were eager to exchange sex for iron. This trade became so extensive that the loss of nails started to threaten Dolphin's physical integrity. See also European and American voyages of scientific exploration Notes References External links Log entry from Bougainville aboard HMS Dolphin, 1768 Exploration ships of the United Kingdom 1751 ships Ships built in Woolwich Sixth-rate frigates of the Royal Navy