Bow thruster noise machine

davidjackson said:
My new boat has one and it's fantastic. I use "all available means" to help me manoeuvre the thing. Sure, I use wind and tide but if I have a bow thruster, why wouln't I use it.

Why be so critical of others? Take a chill pill.
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Indeed.

I have never felt the need for one on an under 50 foot sailing yacht, but over 50 feet it starts to be damned useful in tight spots.

Bow thrusters do a few things which can't be done nearly as well without them, no matter how much seamanship you have:

1. Steer the boat while reversing. Having a thruster is like having a rudder at both ends of the boat; incredibly useful when reversing into or out of a tight spot.
2. Moving the boat sideways off a wall or pontoon (using counter rudder plus thruster). You can spring off to do this, but this is not just more laborious, it is riskier (rope doesn’t run through smoothly; rope gets into the water and into the prop; etc.). Being able to move the boat directly sideways is incredibly useful when you are moored up alongside with no room ahead or behind.
3. Hold the bow up for a few seconds when the wind is blowing it off.
4. Displace the boat towards one side with counter-rudder plus thruster when maneuvering in a tight spot.

It is true that there are plenty of w@nkers who try to use bow thrusters as a substitute for decent seamanship, especially on motor vessels. But maneuvering using a thruster is actually more complicated and requires more, not less skill, to use well. I would not want to be without the thruster on my 54' yacht (60' LOA), and might not even mind having one on a smaller boat, although I spent decades springing off smaller vessels, using prop walk to good effect, etc.

I suspect that there may be some "thruster envy" at play behind some of these negative remarks.
 
Dockhead said:
Indeed.

I have never felt the need for one on an under 50 foot sailing yacht, but over 50 feet it starts to be damned useful in tight spots.

Bow thrusters do a few things which can't be done nearly as well without them, no matter how much seamanship you have:

1. Steer the boat while reversing. Having a thruster is like having a rudder at both ends of the boat; incredibly useful when reversing into or out of a tight spot.
2. Moving the boat sideways off a wall or pontoon (using counter rudder plus thruster). You can spring off to do this, but this is not just more laborious, it is riskier (rope doesn’t run through smoothly; rope gets into the water and into the prop; etc.). Being able to move the boat directly sideways is incredibly useful when you are moored up alongside with no room ahead or behind.
3. Hold the bow up for a few seconds when the wind is blowing it off.
4. Displace the boat towards one side with counter-rudder plus thruster when maneuvering in a tight spot.

It is true that there are plenty of w@nkers who try to use bow thrusters as a substitute for decent seamanship, especially on motor vessels. But maneuvering using a thruster is actually more complicated and requires more, not less skill, to use well. I would not want to be without the thruster on my 54' yacht (60' LOA), and might not even mind having one on a smaller boat, although I spent decades springing off smaller vessels, using prop walk to good effect, etc.

I suspect that there may be some "thruster envy" at play behind some of these negative remarks.
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Quite right in what they can do and what they can mask. The argument holds at any length though, it means for example, you can get into smaller spaces, or go stern to in a crosswind where it would otherwise be impossible.
And I dont have to bother springing off below about a F4. I can, but why would i want to, its a hassle.
 
Dockhead said:
...I suspect that there may be some "thruster envy" at play behind some of these negative remarks.
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+1

I'll be the first to admit I could have done with one on a few occasions. Recently, I came alongside the club pontoon to offload then, as it was getting a bit late, decided to stay put for the night. The next day, the (unforcast) wind was F5-7, blowing me straight onto the pontoon. With boats only a few feet away each side, I took the seamanlike decision that the risk of hitting something trying to get off was just too high. As a result I was a day late getting home, with consquent loss of brownie points. A good strong bowthruster on my 24' Snapdragon would have saved a lot of hassle :)
 
There's a lot of arrogance/snobbery in some sailing quarters. If there is some kind of electronic/mechanical assistance which helps whatever discipline you are taking part in.......just use it, why on earth wouldn't you? Not everyone are highly skilled sea-gods as some obviously are on here.
As a private pilot, I use electronic equipment to guide me. Of course, I also use aviation charts with routes/wind offset etc clearly marked. They have plenty of detail, and I would get there quite safely, but if the weather closes in, and visibility becomes a bit critical, it's good to have a magenta line to get me to my destination whilst avoiding controlled airspace. Nobody in GA criticises a pilot for using GPS, yet use a bit of modern day equipment on a sailing boat, and criticism flies from certain quarters.
I just don't get it
 
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Anybody see the "Mighty Ships" programme last night on the 'Quest' channel?

It was about the curiously-renamed cruise ship Wind Surf, which has five masts supporting seven sails, as well as the diesels needed to shift her vast city-block superstructure.

The docking of this big motor-sailer had been virtually crippled by the failure of her bow-thruster. Throw in a tardy, monoglot pilot at Messina, and there was nearly a nasty incident. Doubtless exaggerated for the camera, but I couldn't help reflecting that in the old days even large sailing ships coped, if not quite as independently, without these aids.
 
nicho said:
There's a lot of arrogance/snobbery in some sailing quarters. If there is some kind of electronic/mechanical assistance which helps whatever discipline you are taking part in.......just use it, why on earth wouldn't you? Not everyone are highly skilled sea-gods as some obviously are on here.
As a private pilot, I use electronic equipment to guide me. Of course, I also use aviation charts with routes/wind offset etc clearly marked. They have plenty of detail, and I would get there quite safely, but if the weather closes in, and visibility becomes a bit critical, it's good to have a magenta line to get me to my destination whilst avoiding controlled airspace. Nobody in GA criticises a pilot for using GPS, yet use a bit of modern day equipment on a sailing boat, and criticism flies from certain quarters.
I just don't get it
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I am used to aviation too, as a photographer in anything from Cessna 172's to a souped-up Hawk; the aids you refer to are GPS which is spiffing in the air or afloat.

Over-reliance on a bow thruster is a sign of poor seamanship, leading to contintuation of the theory among yotties that a lot of mobo owners drive the thing like a car, waving the cheque book when it doesn't work out and someones' pride & joy gets pranged !

I happen to know it's not that simple, and motor boats can be a sod to handle at close quarters, low speed - all windage, no grip on the water - I have as a job handled a 128' single ( big slow revving ) screw barge, so I know what it's like.

However I'd rely on boat handling first, the bow thruster a short term aid at the last minute maybe, but certainly not relying on it - there's always ' the what if it fails ?! ' scenario any good skipper or pilot will have at the back of his mind.
 
Lakesailor said:
I find bow thrusters an anomaly. The noise is surely cavitation, isn't it?
Why has no designer produced a longer-pitch, slower-rotating design which just moves water?
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requires a bigger power source, much of the noise is as you say, cavitation , amplified by the air space above water, inside the vessel also the gearing system.
Have you ever been on a deep sea vessel with this system fitted. Its body shaking noise is not very pleasant especially when testing after refit.
 
I love mine. Pull into our berth, SWMBO a bit slow at getting a line onto the pontoon just give a quick blip on the bow thruster and we are moving back towards the pontoon. Whats wrong with that?

I could "go round" and have another go I suppose but why bother?
 
Well I have one and very rarely use it. But then I do have a deep fin keel and dirty great spade rudder, so shouldn't really need to that often! However, weirdly enough I used it just recently to kick the stern in - mine is so powerful that the boat pivots around the keel. So I thrusted out on the bow (which was in nicely to the pontoon), the stern moved in enough to get a line on a cleat, then thrusted back again to bring the bow back having secured the stern - and it worked, just about! I know the experts on here will still tell me its my fault for not having the stern in close enough in the first place but, on this occasion, I had to use a little more astern than normal to slow down and the prop walk pushed me out. Personally, I can't see anything wrong with facilities/tools that assist safer boating, bow, stern or any type of thrusters.
 
Stoshak said:
Seajet,

You gave us your opinions on twin ruddered yachts drying out. Not safe. Damage to rudders etc etc etc.

I explained that they do work and posted a picture as evidence. Dried out many times since with no probs.

But twin rudders mean no prop wash so manoeuvrability not good unless way on. So bow thruster very useful at times.

So I dry out with two rudders, and I have a thruster. Whatever next!
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Some people are born with club feet, others wtih 3 arms. other even more unfortunate blighters with twin rudders have to post here inbetween visits to outpatients.
 
dancrane said:
The docking of this big motor-sailer had been virtually crippled by the failure of her bow-thruster. Throw in a tardy, monoglot pilot at Messina, and there was nearly a nasty incident. Doubtless exaggerated for the camera, but I couldn't help reflecting that in the old days even large sailing ships coped, if not quite as independently, without these aids.
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In the old days the large sailing ships relied on tug boats and an awful lot of warping and kedging. Also, even the biggest ships were a fair bit smaller than you'd think.
 
davidjackson said:
My new boat has one and it's fantastic. I use "all available means" to help me manoeuvre the thing. Sure, I use wind and tide but if I have a bow thruster, why wouln't I use it.

Why be so critical of others? Take a chill pill.
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The OP was pointing out that using a bow(or stern) thruster when the vessel is making way is pointless, which it is; the people who are doing this are ignorant of how to get the best out of the machinery they have undoubtedly paid a lot of money for.

Elessar said:
Lakesailor said:
I find bow thrusters an anomaly. The noise is surely cavitation, isn't it?
Why has no designer produced a longer-pitch, slower-rotating design which just moves water?
Click to expand...
My goodness. A good question in a bow thruster thread. Yes much of it is cavitation.
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The reason is that a slower rotating design would need to be a much greater diameter, so a traditional tunnel thruster would not fit into the forefoot of most yachts; a possible compromise to allow a larger diameter prop with slower rotation and reduced pitch of noise if not less noise would be a rotating gill thruster or a cone jet thruster. The problem would then be the amount of machinery intrusion into the forepeak living area, which would be much greater than a tunnel system. This plus the greater cost and weight of gill or cone systems means people just put up with the annoying noise. The retractable systems offer a middle path to larger diameters, but that's another increased cost.
 
I dislike the noise they make- almost as annoying as a jet ski and when I hear one Zzzzzzzzzzzzzz-zzzzzzzing away I always think "There goes someone who can't handle their boat" Which I know is a totally wrong thing to think.
I probably think that way as they sound so frantic and the bloke using it ( It is ALWAYS a bloke) is often also frantic, red faced and worried looking.

And usually very shouty.

Still, if they get folk out sailing and stop them smashing up too many other boats then that's good.

Luckily I'm very rarely in a marina now so it's not much of a bother any more.
 
Isn't it inevitable? Boat-ownership grows easier by the decade - be it antifouling rather than fortnightly hull-scrubbing, headsail roller-reefing rather than the almost-inconceivably arduous tasks of repeatedly folding, unfolding & hoisting different headsails...or pushing buttons on a plotter and letting the autohelm steer, rather than chartwork & helming...

...on the other hand, lots of labour-intensive (or judgement-intensive) tasks are rewarding to perform and impressive to observe when done with skill and economy of effort. So, equipping a boat with a push-button alternative looks like purposely avoiding the bother of acquiring the skill. That's sure to attract scorn from folk who do it the traditional way.

And anyone who can do it the old way, but fits a thruster to gain the option to take it easy in difficult situations, risks evoking suspicion of being a bit short of grit. Salt? Grit.

I don't expect any reconciliation soon between those who jeer at thrusters because they can manage without, and those who know it makes sense because it makes life easier.

Here's a lovely little hundred-plus thread about bow-thrusters, for anyone hungry for more: http://www.ybw.com/forums/showthread.php?395860-Can-classic-boats-have-bow-thrusters
 
My point, lest it be forgotten and maybe yes, perhaps was a little obscure,

I'm NOT anti bow thruster.
The bow thruster has it's benefits but more importantly, it has its place.
But there should be a large warning notice pointing out when and where it should not be used.
In still water I have used it and recognise it is an effective aid.
However in a tidal flow, such as on tidal rivers and estuaries the bow thruster significantly loses it's effectiveness.
A fact that some owners fail to appreciate, often until its too late.

It may well be that with the advent of marinas and locked in moorings behind a sill, many people have lost the skills to manoeuvre their boats in a confined space in tidal flow.

I move all sorts of boats almost on a daily basis.
Today for example a Sealine T50, a First 34.7, a Ranger 36, a 45' heavy 1950's motorsailer, and an Atlantic 21 rib.
The wind and tide effects each differently and each requires different inputs at slow speeds and remember even when you're moored up, in a tidal flow you are still moving through the water.
Turning any of these round in the river and mooring up would be far harder using a bow thruster than using the wind, tide and conventional power.
 
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