Single Swimming Arm is a single arm that swims.
The arm is modelled on a human arm and comes in a variety of lengths, colours and muscularity. It terminates in a hand at one end and a rounded knob at the other where the joint of the humerus would be (if the arm was taken from a real person) It flexes
at the elbow and the fully articulated hand can also make a range of movements.
Contained within its fake fleshy interior is a miracle of hydraulics, levers, motors, sinews, along with a signal receiver, battery and a controlling chip.
When placed in the water, and activated via a remote control, the Single Swimming Arm does exactly what it was designed to do. ie it starts swimming. This is its sole purpose and function. It can swim in circles like an orbiting fish or it can zig zag along in a straight line. It can make lazy casual strokes or it can really splash about.
Inevitable deluxe Single Swimming Arm can be fully customised with tattoos, jewellery, scars, watches etc and can be displayed in a cabinet when not being deployed in the nearest lake or swimming pool.