So yesterday i fitted all the RC gear, and decided to carry out a weight check. Without the LIPOs, the all up weight was 3 kg. My 2x 3S 5000mah LIPOs weighed in at 700g, giving a total of 3.7 Kg. Now my original target weight was 3.1 kg, based on a full-size weight of 18,000 kg, so i was a bit concerned that i was over weight, and would have to use some much smaller batteries, which would adversely impact performance and endurance. So this morning i decided to carry out a tank test, and check the waterline. To my surprise, even with the batteries fitted, she was riding high in the water at the stern. A 200g battery placed on the aft deck brought her down to her marks nicely. So i am extremely chuffed! I believe this can be explained as the weight i was working off from the drawings, must be excluding fuel and stores. The fully fueled up and loaded boat must weigh a fair bit more.