 Hi mates, here are the answers to the questions raised.
The volume of water that moves through a canal lock is found using a slightly modified version of the formula, v = l x w x d. We know a lock is 261.8 meters long, 24.4 meters wide, and has a lift of 14.2 meters. In this particular case we are using lift instead of depth because a lock always maintains a certain depth of water and we are interested in how much water moves through a lock and not the total amount of water it can hold. So lets re-write the formula as l x w x lift = v, substitute for the variables and do the calculation. Therefore 261.8m x 24.4m x 14.2m = 90,708.464 cubic meters. This is the amount of water that moves through a lock during the locking procedure.

The second question asked was how many fish tanks could we fill with the volume of water that moves through a lock during the lifting or lowering of a ship. Well, we know that the volume of water moving through a lock is 90,708.464 cubic meters and that our fish tank has a volume of 30 cubic feet. The first thing we need to do is make sure that all our figures are using the same unit of measurement. In this case we need to convert one of our figures to the other figure's unit of measure. A conversion chart shows 1 cubic meter is equal to about 35.3 cubic feet. If we multiply 90,708.464 cubic meters by 35.3 we will get 3,202,008.7 cubic feet as our volume of water. We can now divide 3,202,008.7 cubic feet by the size of our fish tank - 30 cubic feet, to find out how may fish tanks we can fill. The answer is 106,733.62 fish tanks. Holy macerel, that is lot of fish tanks.