Over on his blog Jonty Pearce is weighing up the pros and cons of a bow thruster


Our Southerly 105 ketch is a heavy old girl with high freeboard, a raised cabin, and lots of rigging to catch the wind. Her 1 ton triangular cast iron keel could not be described as belonging to the slim fin brigade. When all is taken into account, she is not an agile boat to manoeuvre in confined marina spaces, especially when the wind is up. I admit she is not as stubborn as a long keeler in reverse, but she can have her moments. More modern versions of the Southerly sprouted twin rudders to enhance performance under sail, particularly when heeled. This, however, lost them the benefits of prop wash when in forward gear, and the resulting potential clumsiness when trying to turn in their own length meant that the majority of production boats were fitted with a bow thruster.


I have mixed feelings about bow thrusters – on one hand I think they are a cheat for those who don’t know how to handle their boats, and on the other hand I wish I had one when I mess up getting Aurial in or out of her berth. For the majority of time they are unnecessary; the revealing ‘whizzing buzz’ as a yacht turns sharply into a berth a 7 year old could not have missed seems only essential to broadcast the boast that one is fitted. And using the bow thruster to hold oneself alongside a pontoon while mooring up is simply caddish. The pits of disrespect applies to those motor boating colleagues who have one each end and just slide sideways when berthing – disgraceful! But when Aurial’s bow is being blown sideways off her pontoon and she ends up drifting towards the opposite line of sharp anchor fronted boats I do consider the practicalities of fitting one…


Aurial sits bow in and port side to in her berth. Her prop walk pulls her stern to port, somewhat hampering the task of departing for sea. When we cast off, I have to motor astern and try to turn her stern to starboard against the prop walk. Lots of revs are not the answer here – the balance lies between getting on enough way and exacerbating the prop walk with a racing engine. I try to get over the magic speed of 1 knot astern on low revs, then put the motor out of gear with the rudder moderately over to allow the flow to pull the stern round. If I’m lucky and the wind is not bad tempered, I’m then able to give a sharp short burst ahead with the rudder hard to port just before I entangle with the boats on the pontoons astern – the relief of seeing the bow smoothly driven round by the prop wash is always a pleasure. With more luck, and as long as a northerly breeze does not interfere, the bow will clear our neighbouring yachts and I am able to breathe again. But when the north wind doth blow and the bow backs round I do entertain the fitting of a ‘cheat stick’ in the form of a bow thruster. Afterwards, I consider the cost, the electrics, and the large hole in the bow with its associated drag, and decide to defer the decision till next year.


Carol, of course, is against the fitting of a bow thruster – ‘no more holes in the boat’. She also has a strange and inexplicable faith in my boat handling abilities, doubtless because she is always at the wrong end of the boat to observe the sweat trickling off my brows and dripping from my damp palms. The conclusion? Do nothing, and continue trying to improve my seamanship by perfecting the balance between prop walk and prop wash.

Jonty Pearce