Abstract: A portable draft measurement device for measuring the draft of a vessel including a tube having an upper end, a lower end, and an interior volume between the upper and lower ends. The device includes a valve fixed to the lower end of the tube, and a resiliently biased valve actuator coupled with the valve and accessible through the upper end of the tube for selectively opening and closing the valve. Selectively opening the valve with the lower end of the tube immersed in the water in which the vessel floats, produces a level of water within the interior volume of the tube indicative of a water-line on the vessel. Selectively closing the valve retains the level of water within the interior volume, whereby the device can be removed from the water and transported to a location where the level of fluid can be measured as against a measuring tape observed through the tube.