Review: Edson Autopilot Tiller Arm

Edson sell a range of Auto Pilot Tiller arms. I'd never heard of these before, but they appear to be a solution to a potential problem which is up there in the top two or three worst things that could happen offshore - steering failure. The principle is that rather than attaching the drive mechanism of the autopilot to the steering quadrant, the tiller arm is attached to the rudder stock and the autopilot mounted to this instead. So in the instance of failure of the wheel steering, it is possible to steer the boat home using the electronic autopilot.

They are available in a variety of sizes and a choice of Bronze or an Aluminium. Bronze for cruising boats with Stainless or Bronze fittings and Aluminium for Composite or Aluminium rudder posts. They cost around $400 - $550 depending on size and material, which doesn't feel extortionate.

In principle I think this is a great idea - reducing the single points of failure on a boat is always a worthy goal. My main question however is of all the incidents of recorded steering failure, what percentage are upstream of the quadrant? What I mean by that is that redundancy is great if the majority of problems occur on the quadrant itself or in the steering wire connecting the wheel to the quadrant. If however a significant portion of the faults occur in say the rudder bearings or as a result of hitting a submerged object, then this backup option is unlikely to be of any help.

On balance: When I come to fit a new linear drive autopilot to my boat next year, then I'll strongly consider getting one of these. As well as providing some king of additional safety factor, I have a strong suspicion that it'll many the job significantly more straightforward.