Abstract: The subject pole is used to help propel a person on ski floats or water walkers. Each pole comprises a shaft with a hand grip at the top end and, in order from the bottom end: a small float, a propulsion apparatus and a larger float. The floats are bodies of revolution. The propulsion apparatus is a shell of revolution with a semi-elliptical shape and the long axis of the ellipse coincident with the longitudinal axis of the shaft and the open face of the shell facing the bottom end of the pole. The shell is slotted in four places to form four petals. The ends of the petals are interconnected by a garter spring. Also each petal is connected by two ties to a flange on the small float. In use the pole is moved fore and aft in alternate thrust and return strokes. It is at an angle to the water surface with the grip end higher and planes on the water surface in the return strokes and submerges to a depth limited by the buoyancy of the larger float on the thrust strokes.

Abstract: The subject apparatus comprises a pair of floats, each having propulsion apparatus attached to its bottom. There is a foot well in each float, extending from top to bottom and fitted with toe retaining and heel support elements. The propulsion apparatus comprises an I-beam having a top flange, web and bottom flange and pairs of flaps hinged to the web, one of each pair on each side of the web. The pairs are spaced equidistant from each other along the web. The hinge axes are vertical. Each flap hinges between the closed position (against the web) to the open position (about 90.degree. to the web). The longitudinal axis of the I-beam is parallel to the longitudinal axis of the float to which it is attached and the web functions as a keel. The bottom flange is angled slightly upward toward the front end. The midpoints of the lengths of the foot wells and propulsion apparatus are somewhat aft of the lengthwise midpoints of the floats. The propulsion apparatus is about half as long as the float.

Abstract: Sandwich panels comprising a top skin and a bottom skin and a connecting core of a plurality of strand connectors are fabricated by applying viscous liquid core material to one of the skins, providing particles with the viscous core material, and reciprocating the particles between the top and bottom skins to form the strand connectors. The strand connectors are permitted to solidify to complete the formation of the sandwich panel. The particles are preferably of a ferrous metal and are driven between the top and bottom skins by a controlled magnetic field. Compound curved and tubular sandwich panels can be formed by the method.