A close-up of three water sampling bottles on the forecastle on board the Royal Research Ship Discovery (1962) while at sea. The bottles are numbered 4, 5 and 6. Number 4 has one sampling tube in it, Number 5 has three and Number 6 has two. Each sampling tube has a different number painted on it in red. This is Slide 15 of Captain Henry P. Bird's lecture titled "Deep Oceans", about his service as Third Officer on board the Discovery from 15 December 1971 to 16 April 1972. The ship was on a Marine Biological Cruise to the seas off Cape Bogador in Spanish Sahara (now Western Sahara), off the southern tip of Fuerteventura in the Canary Islands, around the Cape Verde Islands and along the West African Shelf off Nouakchott in Mauretania. She sailed from Barry on 4 February and returned on 16 April 1972. The lecture consists of 78 slides.