Abstract: Device (1) creates slow-relative-motion hydrodynamics in a cycling hull (10) when multiplicity of hull sections (11) moves between multiplicity of rotatable end waterline turnabouts (20) and multiplicity of rotatable keel turnabouts (30). When device (1) moves across water, multiplicity of hull sections (11) cycles via connection to pivotable connection (12), which pivots about multiplicity of rotatable end waterline turnabouts (20) and multiplicity of rotatable keel turnabouts (30). This puts cycling hull (10) in motion. Since the bottom of multiplicity of rotatable keel turnabouts (30) is lower than the bottom of multiplicity of rotatable end waterline turnabouts (20), the portion of cycling hull (10) moving between multiplicity of rotatable end waterline turnabouts (20) and multiplicity of rotatable keel turnabouts (30) also travels the full draft of device (1).

Abstract: Disclosed is a device for facilitating direct arm-and-leg tandem (quadrimanual) production of the power stroke in forward-facing rowing that allows the placing of the oars into the water for the power strode and the clearing of the oars from the water in the recovery stroke to be done with the arms independently of the legs. Starboard side pivotable vertical axis (100 and port side pivotable vertical axis (11) provide the means for starboard side off-set pedal bar (4) and port side off-set pedal bar (5) to pivot in a horizontal dimension along with starboard side off-set oar (6) and port side off-set oar (7). By pushing forward on the off-set pedal bars and off-set oars denoted, one engages the power stroke in rowing the device. By moving said pedal bars and oars backward, one repositions the oars in the horizontal dimension during the recovery stroke for a subsequent power stroke.

Abstract: A device for facilitating direct arm-and-leg-tandem production of forward-facing rowing is disclosed. It comprises, briefly and generally, as thrust abutment and reclined back rest (30) and seat (40) tilted back to accommodate a convenient placement of handle-and-pedal assembly (50) for one rowing the device. Handle-and-pedal assembly (50) components are attached to oars for one to use in directly powering a watercraft forward by rowing. Oars (70) pivot by means of pair of connected pivotal axes (60). Pair of connected pivotal axes (60)—one pair to each oar—facilitate moving oars (70) through arcs originating with two axes, one longitudinally positioned and the other vertically positioned. The axes (60) are designed to be strong enough to prevent torquing when pedal (58) and pedal bar (56) are attached to the oars as part of handle-and-pedal assembly (50).