its scary to think that you think that you need an auxilary engine when you have sails as well but i suppose in calm conditions with no wind at all and a rope around your prop 4 hp would mybee get you out of trouble
4 hp will undoubtedly move you in a flat sea and no tide, but suggest that you need to look at the high thrust Yam 9.9hp as a better bet. Even with that you will have trouble in bad weather, but more because the engine will be being lifted out of the water by the boat movement unless you mount it inside the boat in a well.
Hi 9.9 no less.Fitted on to my boat. Very pleased. Getting out of tight rafts a piece of cake. You will have to get to o/b as low as possible,to minimise the lifting out
Agree with other posts....Yamaha 9.9hp 4-stroke with the extra long shaft, high thrust prop and "high" output alternator.........unusual for a Berwick not to have an inboard diesel tho.....