The difference between Patent log and Taffrail log
When used as nouns, patent log means a taffrail log, whereas taffrail log means a mechanical device dragged from the stern of the vessel that indicates the vessel's speed through the water.
check bellow for the other definitions of Patent log and Taffrail log
-
Patent log as a noun (nautical):
A taffrail log
-
Taffrail log as a noun (nautical):
A mechanical device dragged from the stern of the vessel that indicates the vessel's speed through the water; usually consists of a propeller, a reading unit and a stiff line connecting them.