A watercraft includes a hull and a water diverter. The water diverter comprises at least one first deflector configured to direct water upward and outward from the hull of the watercraft to create a wave. The water diverter may include a support structure in the shape of a hollow tube for the first deflector, and a second deflector positioned above the first deflector. An entanglement system for defending watercraft includes a main cable attached to the watercraft and at least one strand section. Each strand section includes a connector and a plurality of strands attached to the connector, and each strand section is attached to the main cable. A defense system for watercraft can include both a water diverter and an entanglement system.