On July 10, 2006, at 1724 Pacific daylight time, an experimental amphibious Palmer Seawind 3000, N8025Q, caught fire following an emergency landing on the water near Clear Bay on the Lower Colorado River's main channel of the Lake Havasu National Wildlife Refuge, near Havasu Lake, California. The emergency landing was precipitated by a strong electrical smoke in the cockpit. The water landing was successful, but the airplane was destroyed during the ensuing post impact fire. The pilot/owner operated the airplane as a personal flight under the provisions of 14 CFR Part 91. The private pilot and one passenger were not injured. Visual meteorological conditions prevailed for the flight that departed Lake Havasu City Airport (HII), Lake Havasu City, Arizona, about 1700. No flight plan had been filed. The flight was destined for French Valley (F70), Murrieta/Temecula, California. According to an officer from the United States Fish and Wildlife Service, a call was received from the pilot at 1730 indicating that he had been involved in an accident. In the pilot's written statement he reported that his intent was to do 4 or 5 water landings before heading to F70. On the first landing and takeoff everything was normal. During the takeoff initial climb to conduct another landing, about 150 to 200 feet above the water, he began to smell electrical fumes and immediately observed smoke emanating from the forward right vent of the instrument panel. He immediately turned off the MASTER switch and noted that smoke was still coming from the vent area. He lined up on the river and landed in the shortest time he could. He reduced the power and on short final retarded all of the levers and turned off the magnetos. After landing, he opened the canopy and instructed his son to exit the airplane. As the pilot went to retrieve the fire extinguisher, there was a "fireball of flames." He also exited the airplane. Neither he nor his son was injured. The National Transportation Safety Board investigator-in-charge (IIC) interviewed the pilot. The pilot indicated that he had purchased the airplane in September 2005, and it had been in a maintenance shop for 7 months. He further indicated that a King Global Positioning System (GPS) had recently been installed. He reported that he had been flying the airplane for about 3 months. A Safety Board investigator examined the airplane at Air Transport, Phoenix, Arizona, on October 29, 2006. Two Odyssey Extreme drycell batteries, which were interconnected in a tandem configuration, powered the airplane. The batteries were secured to a wall on the right side nose/storage compartment area. There were two solenoids that the batteries were connected to, a MASTER and a START solenoid. Each battery had their own positive and negative cables that were then connected to the solenoids. The battery compartment had a burn mark on the side that corresponded with the size and position of the negative cable on the right side battery. The right battery cables' protective coverings were burned and melted off. The protective covering for the left battery cables were intact until they passed through the firewall. The Safety Board investigator noted that after the cables passed through the firewall, the positive cable for the right battery had melted together with the negative cable for the left battery. In addition, the cables had sustained thermal damage, with 3 of the 4 cables separated on the cockpit side of the firewall. The fourth cable, the negative cable for the left battery remained continuous. Additional inspection of the airplane's electrical wiring by personnel from Aircraft Engine Reconstruction Specialists, Inc., Prescott, Arizona, revealed that the groundside of the forward 24V battery had been wired to the "hot side" of the START solenoid. This would result in a reverse polarity draw during engine start, and a short would occur anytime the starter was energized. Paperwork obtained from Airmech, Inc., dated August 8, 2006, indicated the company moved both batteries to the right side of the nose and rewired the cables to the batteries and solenoids. According to a representative from Seawind, for the experimental airplanes such as the accident airplane, the requirement was for the installation of one battery positioned on the right side nose storage/compartment area at bulkhead 36. The directions also contained information on how to cover the battery and placement of the MASTER and STARTER solenoids. A basic electrical wiring diagram was provided to kit builders.