In these days of modern satellite-based navigation systems, chart-plotters and mobile phone apps, its hard to imagine that instruments like this were once essential when navigating the course of a vessel at sea. As a young man living on my boat on the South Coast of England, I well remember owning this exact same model and using it when out at sea. It was a brilliantly simple piece of kit. Mine was eventually lost overboard in a particularly rough sea off the Dorset coast. No doubt it's still there!

This is an antique 'Excelsior III' ship's log by Thomas Walker of Birmingham, designed to be affixed to the vessel's taffrail with the rotator towed astern, with the distance travelled being recorded by a system of internal mechanical cogs which turned the needles on the display.

This example is attractively mounted together with its original rotator on a display stand. The enamelled plate reads "Walker's Excelsior III Patent Log, Made in England by Thos. Walker Ltd of Birmingham", with the principal dial being marked in tens of nautical miles up to a maximum of 100, and the subsidiary dial from 0 to 10 nautical miles divided into quarters. It most likely dates to the 1930s. Mounted on a stand it measures 61cm x 18cm x 17cm.

Condition: The instrument survives in excellent condition with just a little normal tarnishing to the brasswork. The enamelled dial is in excellent condition. Glass intact. Display stand a recent addition in excellent condition. The instrument has not been tested. The nautical chart which appears in the background of the images is not included.