The navigator making an amendment to the chart of Southampton on board the 3-masted topsail schooner Sir Winston Churchill (1966) when under sail in Southampton Water. He is at the chart table on the port side of the main deck in the officers' mess. A document on the port bulkhead reads "Springs Fri 25th" and in 1975 the 25th was on a Friday in April and July and only 25th July coincides with a spring tide. The photographer is looking to port from the centreline.