| Title | Ballasting of ships |
| Caption | This is a pig iron bar used for ballast on the HMS Endeavor. It was recovered in 1969. The HMS Endeavor hit a reef in 1770 and the Captain decided to jettison some of the heavier cargo to float the vessel off the reef. |
| Source | http://www.nma.gov.au/collections/collection_interactives/european_voyages_to_the_australian_continent/empire/endeavour_runs_aground/ |
| URL | http://www.nma.gov.au/collections/collection_interactives/european_voyages_to_the_australian_continent/empire/endeavour_runs_aground/ |
| Creator | George Serras |
| Type | Photograph |
| Origin | Internet |
The OED defines "ballast" as follows: "Any heavy material, such as gravel, sand, metal, water, etc., placed in the hold of a ship to weigh it down in the water and prevent it from capsizing when under sail or in motion."