In common with many sailors, I rather regret the need for auxiliary power, but of course it is an enormous convenience and a significant contribution to safety.
Haiku’s plans have an optional outboard well, but I have seen the outboard in Alastair Bremner’s boat and I have to say I was very surprised at how much of an intrusion into the cockpit it was. If I were to use the same arrangement, it would seriously call into question whether this was the right boat for me at all, since a day sail with six people would become very cramped.
One of the other criteria that led me to the choice of Haiku was the extreme shallow draft, and here is another potential area of conflict with the auxiliary power. There seems little point choosing a boat with a 1ft draft, if you then dangle a propeller in the water that requires 2ft. This led me through all sorts of wild ideas involving jet drives and the like, but not only does there seem to be nothing on the market of a modest enough power, I am also assured that jet drives are hopelessly inefficient except on high-speed craft.
A further constraint is my unwillingness to contemplate an inboard motor. Interestingly, Iain Oughtred is extremely scathing about the idea of an inboard on this design. I can’t be sure of all his reasons, but my objections include the following:
- The modifications necessary to fit an appropriate inboard in the boat, e.g. a much enlarged compartment beneath/near the bridge deck, and the addition of a skeg to carry the drive shaft aft and protect the propeller.
- Another hole in the hull to inspect and worry about
- Noise, right in the heart of the boat, whenever motoring is necessary
- The in situ maintenance required, especially bearing in mind I will not be a regular visitor to places that have such facilities
So where does that leave me?
The first thing that occurs is to go electric. This would eliminate some of my concerns above, but of course it brings its own problems, not least of which is cost!
By far the simplest and cheapest implementation of the electric idea would be to go with a Torqeedo outboard. I could create the outboard well, and at least the head of the outboard is tiny compared with a 10HP petrol motor, so the intrusion into the cockpit would be considerably less. Another option would be to mount it on a bracket on the outside of the boat. However, my gut feeling is one of dislike for outboards both in terms of their inconvenience and looks, so I will only use this as my fall-back position.
The idea that is currently my front runner is to use an electric pod drive. An obvious make would be Mastervolt, but I did see some pods recently by Krautler, which looked very good. A folding propeller obviously reduces drag, but also helps in that there is otherwise insufficient draft to allow the boat to dry out without damaging the propeller.
Of course this still leaves the thorny issues of power source and storage. Again, I have no firm conclusion here, but am thinking of a generator coupled with enough batteries to give me about 1 hour motoring at full power. This does not sound much, but the generator could be rated so as to enable motoring at reduced power for as long as the fuel lasted. One such generator would be the diesel-powered Paguro 3000 Compact. Fitting this in would require a minor modification to the space under the bridge deck, but nothing like the modification needed to fit an inboard motor of a suitable size. It also introduces something that needs maintenance, but my understanding is that it would not be difficult to remove and take somewhere for servicing if necessary. Another option of course would be a Honda petrol generator – simple, cheap and portable, but does involve bringing petrol onto the boat.