the center of gravity cg of the aircraft in flight exceeding the cg envelope can create an unrecoverable flight attitude situation particularly in flight just a few feet of the surface of a body of water one method of controlling water position is to fill multiple smaller discrete tanks this has the apparent drawback that the combined empty weight of the tanks is increased relative to the water capacity of the system as a whole thereby decreasing the effective capacity illustrated in fig2 is a water tank 300 and associated filling system 310 carried within the fuselage 120 in the depicted embodiment the filling system includes a manifold 312 water is directed towards the holding tank 300 via the manifold 312 for example via probe 210 during an in flight water pick up the holding tank 300 may also be filled while the aircraft is on the ground either via the manifold 312 through an optional other fill port in the case of ground based filling speed is optimal over maintaining stability of the water load considering then in flight water pick up water is directed from the probe 210 to the manifold 312 the intake manifold is in fluid communication with a plurality of valves 314 a 314 b 314 c etc via a corresponding plurality of conduits 316 a 316 b 316 c respectively alternately the configuration may include on such conduit one on each.