Boat Handling Under Engine – Part 4: “Gliding, Warping and Winding”
Most students that we teach on Amelie Rose have heard of ferry gliding but few seem able to nail it on the first attempt. Like spinning the boat, it’s a technique that’s worth mastering however as it can get you and the boat safely away from many a hairy situation. It will also develop your awareness of how the boat is moving relative to the fixed objects around you. Watching a boat ferry gliding backwards out of a tight fairway is a sight to behold, and a sure fire indication that the skipper knows their onions.
The essential point of the technique is to use the water flow provided by a tide or current to “fool” the boat into thinking that she has steerage without her actually moving over the ground. Of course, there is no fooling going on here at all. As noted in previous articles, if there is enough water flow across her keel and rudder, then the boat DOES have steerage. Furthermore, with enough tide running; tweaking the tiller, throttle and her attitude to the flow of tide will enable us to move her in any direction that we choose relative to the fixed obstructions around.
The difficulty with executing this comes in the number of elements that the helm must process and/or manage in order to exert total control over the placement and movement of the boat. These are:
- Fore and aft motion of the boat (relative to the ground).
- Port/starboard motion of the boat (relative to the ground).
- Maintaining steerage.
- Boat’s attitude to the tide/current.
- Throttle setting.
- Rudder angle.
Putting it all together – Ferry Gliding
The ideal starting point for any ferry gliding manoeuvre is to be stemming the tide. By this I mean fully stemming it. Not creeping forwards, sliding backwards or drifting one way or another but totally stationary over the ground. A crucial corollary to this is to attain this state with steerage (i.e. if you move the tiller then the bow moves in response). Developing this skill is core to all that comes after.
In order to be doing this the boat will need to be facing directly into the tidal set and driving into it at the exact speed of the tidal rate (which needs to be higher than the speed that she needs to gain steerage). These factors can be validated by use of natural transits forward (to monitor sideways motion), abeam (to monitor fore and aft progress) and by occasionally pushing or pulling the helm to establish that the bow moves in response (though the helm must be reversed and then centred again immediately steerage is proven else she will begin to move sideways over the ground).
Bear in mind whilst attempting this that trots of moorings and pontoons around you may well not be aligned perfectly with the tidal set and that it may be necessary to pop the throttle in and out of drive to achieve the requisite speed through the water. Wind pressure to port or starboard of the bow may also require some rudder angle and extra power now and again in order to maintain proven steerage thus the “neutral” helm position may not be “centred” nor indeed static. Lastly, as we will be juggling with the boat’s attitude to the tidal set in order to move her around, any transits that are used must be off the boat (i.e. DON’T use a stanchion aboard and something beyond).
Assuming that the tide is running faster than the vessel’s minimum steerage speed it will now be possible to move her in ANY direction (including backwards) by juggling her keel’s attitude to the tidal set and her speed through the water.
To head to port or starboard push her bow to port (or starboard) of the tidal flow and hold it there. As you do this you will typically notice that she begins to fall backwards even though the engine revs have not changed. This is due to her “showing” more of her keel to the tide – which increases the tide’s effect on the boat and can be counteracted by increasing her speed through the water (i.e. a few more revs).
A common mistake at this point is to forget to put the tiller back to neutral thus continually increasing her turn across the tide. This reveals more and more keel increasing her sideways velocity and also the backwards force exerted by the tide. This is fine if you want her to move more quickly in that direction but remember that it is the keel’s attitude to the tidal set combined with her forward motion against the tide that is doing the work. So, get her moving in the direction you want (established by checking your forward transit) then hold her attitude to the tidal flow by reversing and then neutralising the tiller.
To stop (or slow) her sideways movement simply push the bow back into the tidal flow and reduce the revs until both transits stabilise. All the time that you are ferry-gliding remember that you must also be checking steerage now and again to validate that you still have control of the bow. If you have a speed log within easy sight of the helm and know your minimum steerage speed then this can help – but the key is to keep conducting the practical experiment of pushing the bow up into the wind for a second to prove that you still have her on the leash.
To head forwards is pretty self-explanatory, just increase the revs a little, but ferry-gliding backwards deserves a little more exposition. Essentially all you need to do is to reduce her forward speed until she is travelling through the water more slowly than the tide is carrying her backwards. The temptation here is just to knock her into neutral and let the tide do what it may. The problem with this plan is that you will become a passenger on your way to an accident with the tide in the driver’s seat. It’s imperative that you maintain control of the bow (i.e. keep steerage way) in order to be able to react instantly to any changes in the situation.
This becomes particularly difficult when the tide rate is very close to her minimum steerage speed as it will appear that to gain any backward motion at all requires her to lose steerage. If this happens then do not despair for we already have the answer. Showing more of her keel to the tide will increase the tidal effect as we noted earlier, but will still keep her under control. It will also move her sideways of course and in a tighter space you may need to zig-zag from side to side as she travels backwards to reach your goal.
Lastly, whilst engaged in a backward ferry glide always bear in mind that as far as the boat is concerned she is driving forwards through the water. DO NOT make the mistake of reversing your helm and starting to steer as if you are heading astern or else there will surely be tears before pub-time.
Practice makes perfect:
If this all sounds like a lot to take on whilst booting around the confines of a harbour, well, it is. With this in mind why not find yourself a secluded mooring buoy sat in a good tidal flow on a calm day and have a go at “boxing the buoy”? Start by stemming the tide with the buoy on the beam – about a boat-length away. Now ferry-glide the boat around the buoy keeping the same distance away at all times, bringing her back to stem the tide in the same starting position. Getting it spot on is harder than you might think and it’s a great way to pass an hour or so whilst waiting for a sea breeze to kick in. For an extra challenge, try it in reverse!
Warping and Winding
Back in the days before engines became so prevalent it was common place to move vessels around inside a harbour using warps, muscles and the capstans that used to be stationed at key positions around most quaysides. Today, sadly, capstans are rarely kept in working order, if indeed they are kept at all, and the buzzing of bow-thrusters echoes across most harbours rather than the rhythm of tramping feet and the call and response of a long haul shanty.
Just because we have engines should not mean that we forget the efficacy of some of these old methods however. Many manoeuvres can be made easier – or indeed made possible at all – by moving the boat around with mooring warps. “Modern” traditional boats will often have winches or even powered windlasses to replace those missing capstans and the engine too can be pushed into service to help provide any missing grunt.
There’s any number of ways that warps can be used, however 3 basic manoeuvres get used with reasonable regularity aboard the Amelie Rose:
The “Forward/Backward Shuffle”
Often used to shuffle Amelie Rose backwards along a pontoon to enable us to escape backwards with a freer exit, this has occasionally also involves us shuffling her alongside another vessel that was impeding her exit.
The “t’Other Side Haul”
This is a great way to escape if your prop-kick just isn’t working for you or you’re being pinned on by wind and tide. Obviously it requires that there’s another pontoon or moored vessel available for you to use and you may need some mighty long warps to get there.
“Winding the Boat”
Winding the boat is an idea nicked from our barge-hauling inland brethren. Essentially it means to spin the boat in her berth using the wind to assist. In our case if the wind isn’t assisting then the tide might be or we can always use the engine to step in instead.
Whatever method gets used there are some key lessons that we’ve learned over the years:
Don’t untie anything until it’s proven to be no longer doing anything
Once, with Amelie Rose stuck in an inhospitable corner in Ramsgate, we opted to combine a t’Other Side Haul with Winding the Boat, to both escape being blown on and to face her towards the exit. The resulting cat’s cradle of warps had everyone scratching their heads a bit but allowed us to spin her and haul her across to the other pontoon with no “death or glory” moments.
The key is to remain in total control of the boat at all times – if you stop hauling on the warps then the boat should stop moving. The easy way to test this is to slacken a warp by a foot and watch to see what happens. If nothing happens, great, the warp’s work is done, but if the boat starts to move then you might want secure the line sharpish and think again.
If the boat is moving forwards or backwards it’s also worth pairing up the bow and stern lines. This way one can always be working whilst the other is being moved. There’s no worse feeling than a bow line slipping from your grasp just as you realise that there’s no one aboard right now.
Watch out for the tide
Remember that any manoeuvre that shows more of the keel to the tide may lead to a massive increase in the amount of pressure on the up tide warps. It’s entirely possible to find yourself stuck in a “can’t go forward, can’t get back” situation as an increasing tidal flow pins the boat somewhere unintended. On the other hand – a strong tidal flow may mean that ferry-gliding is now an option!
There is no such thing as too many fenders
This is really rather self-explanatory! Remember that a typical long thin fender with a sail-tie or two fenders partnered together can be used horizontally to produce a fender less inclined to roll out of position (a typical problem when a “blown on” boat is walked along a pontoon). It’s also worth having roving fenders to hand for any unforeseen contacts.
Next time we’ll have a look at how to get ourselves ashore once more as we look at techniques for coming alongside without frightening the natives…
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