The pilot planned to visit a friend and land in a paddock at his property. He noticed the wind direction and speed from wind patterns on the sea, then commenced a survey of the property to find a suitable landing area. He noticed three power lines across the selected paddock, but failed to see a fourth. He then descended from 500 ft above ground level (AGL) to 100 ft AGL for a better look at the intended landing area, then continued the descent to about 25 ft AGL to check the surface conditions. The fourth power line suddenly appeared across the path of the aircraft, and with no time to take avoiding action the aircraft struck the wire with the propeller and windscreen, causing it to pitch nose down and impact the ground. The emergency locator beacon (ELB) activated and was heard by an overflying regular public transport (RPT) aircraft.