A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A mutually opposite generally horizontal gravity-driven flow water toy including at least first and second water inlets, at least first and second generally vertical water conduits coupled to respective ones of the at least first and second water inlets for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets, at least first and second generally horizontal water conduits coupled to respective ones of the at least first and second generally vertical water conduits for directing a gravity flow of water therethrough from the respective ones of the first and second water inlets and via respective ones of the at least first and second generally vertical water conduits, the at least first and second generally horizontal water conduits being arranged such that the gravity flow of water therethrough is in generally opposite directions.

A self-propelled spinning device having a first and second hemisphere connected together to form a hollow housing. A drive system is disposed in the hollow housing and a plurality of projections extends outward from the first or second hemisphere. The drive system includes an eccentric path of rotation causing the hollow housing to spin about a rotational axis. The projections propel the self-propelled spinning device in a forward direction.

A self-propelled spinning device having a first and second hemisphere connected together to form a hollow housing. A drive system is disposed in the hollow housing and a plurality of projections extends outward from the first or second hemisphere. The drive system includes an eccentric path of rotation causing the hollow housing to spin about a rotational axis. The projections propel the self-propelled spinning device in a forward direction.

An underwater robotic device includes a housing unit, a control unit and a propelling unit. The housing unit includes a base seat and an upper cover in liquid-tight engagement with the base seat. The control unit is disposed within the housing unit and includes a circuit module and a center-of-gravity transferring module which is electronically connected with the circuit module. The center-of-gravity transferring module has a movable weight member and a transfer driving mechanism which drives movement of the weight member so as to vary a position of a center of gravity of the underwater robotic device and to control downward and upward moving directions of the underwater robotic device in the water. The propelling unit is connected with the housing unit and is electronically connected with the control unit to produce a propelling force to move the underwater robotic device forward in the water.

An underwater robotic device includes a housing unit, a control unit and a propelling unit. The housing unit includes a base seat and an upper cover in liquid-tight engagement with the base seat. The control unit is disposed within the housing unit and includes a circuit module and a center-of-gravity transferring module which is electronically connected with the circuit module. The center-of-gravity transferring module has a movable weight member and a transfer driving mechanism which drives movement of the weight member so as to vary a position of a center of gravity of the underwater robotic device and to control downward and upward moving directions of the underwater robotic device in the water. The propelling unit is connected with the housing unit and is electronically connected with the control unit to produce a propelling force to move the underwater robotic device forward in the water.