Embodiments include a retrofit pontoon system including a pontoon, the pontoon having a pontoon body defining a first cavity, the pontoon body having a first aperture; a retrofit assembly, the retrofit assembly including a selectively fillable container sized to pass through the first aperture; and a pump. The pump is operably coupled with the selectively fillable container such that operation of the pump selectively fills and drains water from the selectively fillable container, wherein filling the selectively fillable container lowers the profile of the pontoon in the water and emptying the selectively fillable container raises the profile of the pontoon in the water.

A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.

The present invention refers to a hybrid vessel with a ballast system in which the position of the cabin (102) is changed vertically, from emerged to submerged and vice versa, according to the decision of its operator.

Thus, the present invention describes a hybrid vessel with ballast water system comprising at least one cabin (102) and at least one main tank (101) of ballast water, and the tank (101) is connected directly to the CAB (102) or partially above the water level.

The present invention refers to a hybrid vessel with a ballast system in which the position of the cabin (102) is changed vertically, from emerged to submerged and vice versa, according to the decision of its operator.

Thus, the present invention describes a hybrid vessel with ballast water system comprising at least one cabin (102) and at least one main tank (101) of ballast water, and the tank (101) is connected directly to the CAB (102) or partially above the water level.

Recreational watercraft and methods of operating recreational watercraft are described. Recreational watercraft can include an aluminum hull, a plurality of ballast tanks, a first surface defining a first opening that extends from an interior of a ballast tank of the plurality of ballast tanks to an exterior of the hull, a valve configured to selectively open or close the first opening, and a second surface defining a second opening that is fixed permanently open and extends from an interior of the ballast tank through a bottom portion of the hull to an exterior of the hull.

Recreational watercraft and methods of operating recreational watercraft are described. Recreational watercraft can include an aluminum hull, a plurality of ballast tanks, a first surface defining a first opening that extends from an interior of a ballast tank of the plurality of ballast tanks to an exterior of the hull, a valve configured to selectively open or close the first opening, and a second surface defining a second opening that is fixed permanently open and extends from an interior of the ballast tank through a bottom portion of the hull to an exterior of the hull.

Wakeboats that include an aquatic invasive species control apparatus are provided. These wakeboats can include: a wakeboat with a hull; at least one throughhull fitting in the hull of the wakeboat; an irradiation chamber in fluid communication with the at least one throughhull fitting, the irradiation chamber having a radiation source; and at least one water destination aboard the wakeboat. Methods for irradiating invasive aquatic species aboard a wakeboat are also provided. The methods can include: receiving water from outside the wakeboat hull; and irradiating water aboard the wakeboat prior to discharging the water.

Recreational watercraft and methods of operating recreational watercraft are described. Recreational watercraft can include an aluminum hull, a plurality of ballast tanks, a first surface defining a first opening that extends from an interior of a ballast tank of the plurality of ballast tanks to an exterior of the hull, a valve configured to selectively open or close the first opening, and a second surface defining a second opening that is fixed permanently open and extends from an interior of the ballast tank through a bottom portion of the hull to an exterior of the hull.

Recreational watercraft and methods of operating recreational watercraft are described. Recreational watercraft can include an aluminum hull, a plurality of ballast tanks, a first surface defining a first opening that extends from an interior of a ballast tank of the plurality of ballast tanks to an exterior of the hull, a valve configured to selectively open or close the first opening, and a second surface defining a second opening that is fixed permanently open and extends from an interior of the ballast tank through a bottom portion of the hull to an exterior of the hull.

A portable, pumpless water ballast system can be constructed of a flexible water-proof membrane molded or formed of welded panels to make a desired shape, such as cube-shaped when filled with water. Along the top side is an opening for filling the container. A water-proof closure is provided in the opening to prevent water leaking out. An air release valve can be installed near the top area of the container's top or side panels. A handle or strap can also be provided on one or more of the adjacent sides of the container. A plastic threaded drain and closure can be provided on one or more sides to allow for emptying of the container or to attach other features like a hose or other accessory.