For his latest guide Motor Boat & Yachting's resident expert, Jon Mendez talks through how to ferry-glide sideways
Using a tidal current or river flow to move your boat sideways is called ferry-gliding. The term comes from the traditional practice of using the flow of water on a river to move a ferry boat sideways across it. When a good flow of water is present, it provides ‘free’ sideways propulsion with barely any need for oars or an engine.
It works by simply pointing the boat, either bow or stern first, into the flow of water (bow first usually works best due to the pointy shape) and then turning it at an angle across the flow so that one side is receiving more flow than the other. This puts more pressure on the up-tide side, creating sideways movement. The steeper the angle the greater the sideways force.
Of course the flow will also start to push the boat backwards, which you will need to counter using small nudges of ahead or astern so the motion is only sideways and not fore and aft.
It works on all vessels as the hull shape and keel (if present) are what create the sideways motion. On a single-engine shaftdrive craft, such as the Duchy 27 in the photos, control of the angle is done with the rudder alone. On twin-engine craft, this can be enhanced by using alternate engines.
Larger rudders make fine-controlling the angle easier, but all boats can keep control by using some helm combined with clicks of gear, usually just in ahead but also in astern if you inadvertently use too much ahead.
Our Duchy 27 has a relatively long but shallow keel, a single prop, and a fairly small motorboat- style rudder. This allowed us to keep good control at very slow speed in ahead. In astern, the rudder worked to some degree, but being a single shaft-drive boat, the prop walk always wanted to push the stern to port.
This meant that it was very hit or miss – if you got it set up perfectly on approach it would just about work, but any adjustments mid-approach quickly ended in an abort as the boat would always pull to port regardless of rudder position.
So, if your vessel is compliant when bow-to the elements but a little ‘interesting’ in astern, I would only use this very elegant technique when the bow is facing into the wind and/or tide.
Face the flow
Position the boat facing into the tidal flow. You can see this from the back eddies and smoother water at the stern of the moored boats. The aim is to ferry-glide across into the marina to starboard.]
Angle into flow
By turning the wheel to starboard, the water flow over the rudder turns the boat and presents more of the portside to the flow, causing the whole boat to start crabbing sideways to starboard.
Balance tidal flow
The flow will also start to push the boat astern, so use a click of ahead with the wheel still to starboard to keep the boat stationary fore and aft while still ferry-gliding across to starboard.
Increase angle
The steeper the angle the more the boat gets pushed (or ‘ferries’) to starboard. Be careful as it can move quite quickly. Another click of ahead may be needed to keep the fore and aft transit.
Slow down
If you feel the movement is too fast, all you need to do is put the wheel to port to reduce the angle of attack. If that’s not enough, one click ahead and the boat will straighten and stop.
Come back out
Keep that wheel to port to change which side of the boat is facing into the flow. Now the starboard side is facing into it and the boat is moving to port. Maintain the fore and aft transit using clicks of ahead.
If you enjoyed this….
If you enjoyed this….Motor Boat & Yachting is the world’s leading magazine for Motoryacht enthusiasts. Every month we have inspirational adventures and practical features to help you realise your sailing dreams, as well as tests and news of all the latest motorboats.
Plus you’ll get our quarterly Custom Yachting supplement where we share the last on offer in the superyacht world and at the luxury end of the market.
Build your knowledge with a subscription delivered to your door. See our latest offers and save at least 30% off the cover price.
