Effects of Controls

[zoidberg]

I note a YBW popup video clip playing 'Make It Easy On Yourself' and suggesting fitting a bow and stern thruster to enable turning the boat in its own length.

I was taught that a long, long time ago, using just one prop, two gears, and a rudder..... and was expected by an Examiner to demonstrate it within the tight confines of Port Pendennis Marina, without breaking anything.

Who can, and who can't, turn their boat around 360° that way...? Hands on heart.....!

 

[Bouba]

All of us with a single engine on a shaft can probably do it, I’d imagine. But the thrusters are very handy

 

[sailorman]

in years to come boats will not have rudders, just thrusters.

 

[pvb]

I was taught that a long, long time ago, using just one prop, two gears, and a rudder..... and was expected by an Examiner to demonstrate it within the tight confines of Port Pendennis Marina, without breaking anything.

Older, shaft-drive boats can be turned very easily using propwash and prop walk. But newer designs with saildrives don't do it quite as easily.

 

[awol]

I can spin my Contessa in her own length, provided I do it clockwise. Going where I want to in astern is another matter.

 

[AntarcticPilot]

I note a YBW popup video clip playing 'Make It Easy On Yourself' and suggesting fitting a bow and stern thruster to enable turning the boat in its own length.

I was taught that a long, long time ago, using just one prop, two gears, and a rudder..... and was expected by an Examiner to demonstrate it within the tight confines of Port Pendennis Marina, without breaking anything.

Who can, and who can't, turn their boat around 360° that way...? Hands on heart.....!

Anyone who's done an ICC can - it's one of the tests!

 

[AntarcticPilot]

in years to come boats will not have rudders, just thrusters.

And how will that work when sailing?

 

[Kukri]

My ex boat, a 37ft gaff cutter with 12ft of bowsprit, would turn almost in her own length so long as it was to port. The 16 x 8 three blat prop was offset to port and literally inches from a big wooden rudder with which I could deflect the prop wash almost at right angles. The prop walk was deeply unhelpful - go alongside to port an give a touch astern to stop her and she jumped a yard sideways just as you hoped to step ashore to a cleat...

 

[johnalison]

When I was about 12 yrs old I was given the task of turning a 36' Broads cruiser in its own length, at the end of Thurne Dyke. It was easy at the time and I don't remember having any difficulty ever since, with much handier boats. My current boat, an HR 34 with saildrive is not so easy, especially as the helm only goes over about 45 degrees. Nevertheless, as I have said elsewhere, once you get the boat rotating, ie turning, a touch of astern will bring the boat to a halt while continuing to rotate. If you can use the wind it is even easier.

 

[dunedin]

Older, shaft-drive boats can be turned very easily using propwash and prop walk. But newer designs with saildrives don't do it quite as easily.

And sail drive plus twin rudders even more of a challenge. Ditto old long keel and side propellor shaft.

Knowing how to handle your boat without extra assistance (eg from a thruster) is very worthwhile. But in general using available technology wisely, without over reliance, is just good seamanship.

 

[Yngmar]

Older, shaft-drive boats can be turned very easily using propwash and prop walk. But newer designs with saildrives don't do it quite as easily.

A saildrive with a single(!) rudder behind it turns wonderfully, once you've figured out how. The wash is directed straight at the rudder and from there you can deflect it in the desired direction. So to turn such a boat, you put the rudder hard over (which is typically around 45° as someone mentioned - the perfect angle for this), and then give a brief but strong burst forward. It takes a moment to arrive at the rudder, and then it creates a powerful sideways thrust at the stern and the boat begins to rotate around the keel. It also creates a forward motion, which, if undesirable, you can counteract with an equal burst in astern (which will create no wash over the rudder, and thus simply stop the boats forward motion, while keeping it turning). Repeat if necessary.

This works extremely well once you got the hang of it, and the boat can be turned quickly in place using this method. We have often used it to turn the boat in a fairway as wide as the boat is long and we even managed to turn around in the marina in Vila Real during the full flow of the tide (although the dinghy tried to get away and cowardly hide under the stern of another boat, which added some excitement). We've never felt the desire for a bowthruster.

Boats with twin rudders not in line with the propeller are a different story though - but those will typically come with a bowthruster from the factory, because they really need one - there is no wash over the rudders to redirect and thus no other way to turn the boat in close quarters with no flow over the rudders.

A boat I've seen with a bow and sternthruster was a very nice Standfast, a heavy displacement full keeler with a barn door for a rudder, and again this was because the boat wouldn't turn in tight spaces any other way (short of using warps, which you wouldn't want to regularly practice when cruising).

 

[zoidberg]

I seem to recall the Ocean Youth Club made a virtue of turning their large sailboats around - 'winding ship'? - by judicious use of part-hoisted sails.

 

[C08]

Try this on a catamaran with a single main outboard engine 6 ft from either rudder-if you really want to have fun!