A semiconductor testing circuit of the present invention includes a signal line which is connected to a terminal not to be tested and a plurality of terminals to be tested of a semiconductor device; switch circuits for controlling electrical connectiondisconnection between the signal line and the terminals to be tested; and a resistor connected to one end of the signal line. The holder includes clamping structure for securing the holder to a boat wall and accommodating ready attachment to the boat wall and removal for storage without a need for special tools. The blades are coupled with a blade angle adjustment unit so that the angles of the blades can be adjusted at predetermined angles according to the directions and velocities of winds.