Nothing wrong with using the self leveling crack sealer to help fill in the bottom of the hull next to the water channel. Most ships can carry the weight and it puts the weight low in the hull. I've used it in everything from a Gloire light cruiser to a Richelieu class battleship. None of the ships ended up overweight, even when using lead acid batteries. The last two ships I used the stuff in required additional weight added later. The 12 turn Titan motors are rather popular pump motors for full unit pumps in medium to large ships. They draw around 30 amps at full pump and can move 2.5 to 3 gallons a minute with a one unit outlet..