I learned to do this on my tin boat in the early 1970s. Tin boats can get a leak at the worst times. Usually away from home on a trip you've dreamed of for months. Sometimes a leak will appear in an area you can't reach or don't have tools to work on it. As you fish and move on the water the level stats to rise. Head to shore, pull the boat on land and remove the drain plug from the outside of the boat. Replace it on the inside and tighten the plug. When you're on the lake, open the throttle and have your buddy remove the drain plug. The suction at the boat's rear will drain the water from the boat. Make sure you replace the plug from the inside while the boat is at speed. Repeat as needed. This tip could save your fishing day or trip. ( the vintage tin boats did not have bilge pumps and a few today still lack them)
Wizard