Originally Posted by Searider
The hull will drain quicker than you can lift the boat on davits.
Assuming all of the floor boarded area floods to a depth of at least 2 inches. Thats 2.5msq So to lift it just 2 inches might be an extra 125kg compared to lifting the boat alone. You have to lift it to drain it.
The drain hole is about 10cm diameter and based on some fairly basic calcualtions here Flowrate Calculation for a Draining Tank
is probably draining at 8litres a second. So to drain that 125litres will take 15seconds. I'd have expected to be winching faster than 8 inches every minute or it'll be a long slow winch - Not sure how high you are winching but 1m seems likely. At that rate of winching thats 5 minutes of continuous winching to lift 1m. So I suspect you will for a reasonable period of time have the boat with water in the hull pulling against the lifting davits. Also don't know what volume is in the tank...