Hi Richard. I have an electric trolling motor as my backup. It is 55ft pound output.My boat is 4.5 metres, and whilst I would say a petrol motor would give greater range, and power, the electric motor is light, easy to store and as maintenance free as you can get. I put a large capacity battery on the boat to increase range. I use it occasionally at sea. Never had to use it in anger, but it is better than nothing, and in reasonable seas would hopefully at least get me back to shore. In strong currents or rough seas its untested, so depends where you sail. I've had it for 10 years, and spent nothing on it.