Thruster mania

[Sailorsam101]

I've got two sides to this one.

I used to teach for Southern Sailing for 7 years and i was often called upon to teach marina boat handling. As many of you will know their boats were a bit beat up so the odd bump here and there was OK. I used to spend more time teaching the aspects of prop walk and turning on the spot and showing how a burst of full throttle 6 feet from doom can save the day. Anyway never had nor sued a thruster on a yacht as i had gained the basic skills that you should all learn.

but now i've got a 36 ft twin motorboat with a big thruster. I only use the thruster two times..when getting blown on hard and wanting to leave and to keep the boy in while my lady gets off and does the bow line. Never any need to use it for turning.

but no matter who says what we should all be able to handle whatever boat we are on without a thruster in safety...yes i know some marinas are tight and a thruster makes it easy...but the simple answer is don't park there....i won't go into a mooring that isn't easy and that i can't handy easily.

Over the years i've seen so many big bumps from people who just did not understand the basics of tide and wind and how their boat handles. But i guess things will never change!

 

[Iain C]

.i won't go into a mooring that isn't easy and that i can't handy easily.
!

You raise an interesting point there. We all know cars have grown exponentially in size...my nearly new 5 series estate is longer than my old long wheelbase Defender, and to be honest struggles in 30-40 year old multi storey car parks to fit in spaces and get round corners and rely fairly heavily on parking sensors front and rear and "dipping" door mirrors so you can see the wheels when reversing.

Many marinas I guess are of a similar age now, and where a 34' boat used to be considered a pretty good size back in the day, it's often about the smallest in a modern builder's range. Berths that were easy for your "average" yacht of 30 odd foot are now quite a bit tighter for your "average" yacht that's perhaps nearer 40' long and of course one hell of a lot wider and more wedge shaped. And all the marina will care about is packing as many in as possible...

 

[JumbleDuck]

but no matter who says what we should all be able to handle whatever boat we are on without a thruster in safety...yes i know some marinas are tight and a thruster makes it easy...but the simple answer is don't park there....i won't go into a mooring that isn't easy and that i can't handy easily.

It's a bit like having a long keeler. There are some places I know that I (with my skill level) just cannot put the boat safely, and so I don't try to put her there.

 

[JumbleDuck]

You raise an interesting point there. We all know cars have grown exponentially in size...my nearly new 5 series estate is longer than my old long wheelbase Defender, and to be honest struggles in 30-40 year old multi storey car parks to fit in spaces and get round corners and rely fairly heavily on parking sensors front and rear and "dipping" door mirrors so you can see the wheels when reversing.

I feel your pain. My (old) Citroën DS is only 4" shorter than a 5 series estate and it's pretty rare that I can find a parking space long enough. Mind you, my scruffy old Berlingo is even worse, because although it's shorter it has a turning circle about the size of the asteroid belt.

Many marinas I guess are of a similar age now, and where a 34' boat used to be considered a pretty good size back in the day, it's often about the smallest in a modern builder's range. Berths that were easy for your "average" yacht of 30 odd foot are now quite a bit tighter for your "average" yacht that's perhaps nearer 40' long and of course one hell of a lot wider and more wedge shaped. And all the marina will care about is packing as many in as possible...

Agreed, again. My 26' have no problems, but I can see that for many bigger boats older marinas in particular are not easy. However, my encounter this week was at D pontoon in Port bannatyne, which is the visitor one and has lots of room. No excuse there. Without any prompting, my young crew said "Why didn't he just keep well out, start the turn and then let the wind catch the bow and line him up." Out of the mouths of babes and sucklings ...

 

[johnalison]

Was it really that long ago that you have forgotten the very first few times you were on a yacht? Give people credit for wanting to learn.....

Yes, it is a long time since I learned to turn a 36' motor cruiser on the Broads in its own length when I was 12 yrs old. I'm assuming, perhaps wrongly, that these proposed candidates for thruster-tuition will also be taught how to manoeuvre without a thruster, in which case I still remain baffled as to why extra tuition is required in order to use a gadget that will actually make things easier.

 

[npf1]

BTW: Thrusters don't need to be noisy. The boat I've just got has one - I can't hear it and have to push the button, then watch to the bow move, to check it's working. I think this has much to do with the later bowthruster prop design.

 

[johnalison]

BTW: Thrusters don't need to be noisy. The boat I've just got has one - I can't hear it and have to push the button, then watch to the bow move, to check it's working. I think this has much to do with the later bowthruster prop design.

I'm glad to hear that. I'm also puzzled, as a non-engineer, why they all seem to operate in all-or-nothing mode. I'm sure that other electric motors can be persuaded to operate at a range of speeds, and while I can see that this would be an expensive addition to water pumps and windlasses, I should have thought that it would be an advantage to the user.

 

[npf1]

On a Vetus thruster, the older props four blades, but the new ones have six. I say 'new', but they been available for about 6-8 years! It's a straightforward replacement for the cost of the prop.

That being said, my older boat had a hydraulic Vetus thruster with a four blade, and that was pretty quiet too (but not as quiet as the current one). It was it's lack of reliability that taught me to how to handle a 58' 30t long keeler without a thruster, to the extent that I was disappointed when I had to use it!

 

[[3889]]

Also, perhaps you should stop to consider that the vast majority of boat owners are amateur leisure sailors out for nothing more than some pleasure. By and large they don't really care about getting badges for being "the skipper who is perfect and is an expert on everything". So if their boat has a device that makes it easier, therefore less stressful and therefore more pleasure for them, why shouldn't they use it?

No reason not to but this is a sailing forum. I presume, perhaps incorrectly, that people on here are interested in sailing and, by association, boat handling.
It's perfectly reasonable to extol the virtues of an electric bike but don't expect to be warmly received on a cycling forum where the other members may not appreciate your input on how to avoid physical exertion.

 

[npf1]

I'm glad to hear that. I'm also puzzled, as a non-engineer, why they all seem to operate in all-or-nothing mode. I'm sure that other electric motors can be persuaded to operate at a range of speeds, and while I can see that this would be an expensive addition to water pumps and windlasses, I should have thought that it would be an advantage to the user.

They're also available with a 'soft start'. I suspect the high noise examples are due to either a) cheaper thrusters or b) the noise is amplified on some boats due to the boat's design or construction.

 

[girlofwight]

The exception might be those with twin rudders who don't benefit from prop wash over the rudder.

When looking at new Southerlies a while back it was the first thing to be included when pricing the options list!

Yep, moving to a twin ruddered Southerly from a single ruddered Moody, back in 2006, was a short sharp shock, involving a crew dunking. The bow thruster was no nice to have, it was essential. Had a RYA skipper on board shortly afterwards, he couldn’t berth it easily without the thruster either.

These days on a high sided 17ton fly bridge motor boat, I want every possible tool for managing wind and tide, especially when the eddies and gusts can’t be predicted.

 

[DipperToo]

Yep, moving to a twin ruddered Southerly from a single ruddered Moody, back in 2006, was a short sharp shock, involving a crew dunking. The bow thruster was no nice to have, it was essential. Had a RYA skipper on board shortly afterwards, he couldn’t berth it easily without the thruster either.

+1
On the Southerly 110, the prop is virtually between the twin rudders so unless one has a reasonable amount of way, there is effectively no steerage whatsoever.
Agreed that with some judicious planning one can manoeuvre without using the thruster, but in long narrow trots I think I would rather have the thruster as a 'just in case' option.
As girl of wight says, I also had an RYA instructor for a day after purchasing the boat who made similar comments. However, with some speed (and confidence that it will work) and using reverse halfway in a turn, we can turn the boat in its own length or less.

 

[[2068]]

I'm glad to hear that. I'm also puzzled, as a non-engineer, why they all seem to operate in all-or-nothing mode. I'm sure that other electric motors can be persuaded to operate at a range of speeds, and while I can see that this would be an expensive addition to water pumps and windlasses, I should have thought that it would be an advantage to the user.

This is a valid point.

I don't see why my bow thruster control is not proportional. Instead, I have to manually vary the length of the "burst".

 

[[2068]]

Thanks. I gather from browsing the mobo forums that there is a certain amount of frustration at skippers who use bowthrusters to mask the fact that they can't handle twin engines.

It's a little more complicated than that.

On a twin engined mobo, the engines tend to be mounted about the same distance apart for technical and installation reasons.

If the mobo is not too long and pointy, you don't need a bow thruster, because you can use the differential thrust of the engines to move the bow. This was the case on my previous 28ft boat.

On the the current 36ft boat, that simply doesn't work in a stiff breeze unless you are prepared to deploy quite serious amounts of power in the marina, which is generally frowned upon. So what works is to use the engines to get the body of the boat into roughly the right place, with a kick from the thruster to tuck the nose in.

A thruster is also useful to assist in making a really tight turn where you don't want the stern to swing in the opposite direction at all.

.

 

[JumbleDuck]

It's a little more complicated than that.

Thanks for the clarification!

 

[BelleSerene]

am I wrong in my impression that rather a lot of people now use them, or try to use them, to escape their own ineptness at conventional manoeuvring?

No.

 

[Hadenough]

A couple of years ago I went to berth as a visitor in Hamble Point Marina on a Wednesday at about 7.30pm. The marina was almost deserted, the berth I was allocated was close to the shore. As I gently motored towards the berth, I saw one boat with 4 people in the cockpit. One decided to get up and walked along the pontoon, stopping by the berth I was about to enter. He had seen I was singlehanded and came to help. As I glided slowly into the berth I stopped my Fulmar with a spring and tied the stern line. Then walked forward and tied the other spring and bow line. He said that it was a master class in how to park a boat as he always used plenty of forward and reverse, plus bow thruster.

I spent 20 minutes explaining how I did it and how I rigged the mooring lines. I use one line that is 3 times the length of the boat. It is marked in the middle and this is secured to the mid-ship cleat. The ends are cleated at the bow and stern. So two long loops are along the berthing side. Each is a combined breast rope and spring, so you only 2 cleats on the pontoon are needed to secure the boat. This system does not work on pontoon fingers that do not have cleats or box berths like in Holland.

Most people motor too fast approaching a berth, needing reverse to stop the forward motion and prop walk can screw your course (but can be used if you know how it affects you own boat). The bigger the boat, the more it takes to stop it, so think you are berthing a supertanker.

He said he would try it. Hopefully he is now more confident with his berthing.

Wow!

 

[bitbaltic]

Sounds like a good idea. Alas, the Dunning-Kruger Effect tells us that those who most need the coaching least realise that they do.

Only an academic would mention that.

When I was an academic I had a similar study pinned to the cork notice board in my office (do those still exist?) for about ten years.

 

[bitbaltic]

Personally don't think is really fair to be so critical of others, especially when you don't know the boat and the situation for the skipper at the time. Also, perhaps you should stop to consider that the vast majority of boat owners are amateur leisure sailors out for nothing more than some pleasure. By and large they don't really care about getting badges for being "the skipper who is perfect and is an expert on everything". So if their boat has a device that makes it easier, therefore less stressful and therefore more pleasure for them, why shouldn't they use it? Is it better if they are miserable, stressed out and don't enjoy their boat? Maybe they should get lessons. Maybe they intend to, but for now they have just got the boat and struggling with it and don't want to bash into anyone's boat and revert to the bowthruster as an aid to avoiding damage. Maybe their boat is a pig to handle. Lot's of maybe's, but I don't think it's fair to judge everyone at idiots or numpties just because you happen to find the few seconds of noise so annoying.

As an aside, possibly the worst boat handling skills I have seen over 30 years boating are racing crews of so called experts. Invariably they are so busy barking orders at each other, berthing becomes total chaos. In fact many of the "expert" skippers who I observe who like to bark orders, often end up with chaos all around them when berthing. Sometimes I have gone to offer assistance to the "experts" and been assertively told that no help is required. I then watch with amazement as they smash into the pontoon, or usually lose the stern. If you ask me, they are the numpties, not the skipper who uses a bowthruster. Other "experts" who seem know better are the ones that think their sailing skills are so good they try to sail in/out their berth. Boy oh boy I have watched that pantomime unfold with fellow boat owners running all over the place looking for fenders to protect their boat. All the time thinking to myself "what on earth are you thinking buddy? You are clearly not as good as you would like to think you are? Here's another observation. I can't help noticing that the "experts" seem to have the most shabby boats with the most damage to the topsides!! Hmmm......

So, I put it to you m'lud, who are the numpties? The "experts" who think they are so good and cause chaos when it all goes pete tong as it usually does, or the novices who use their bowthruster, make a little noise and berth without drama?

Worst boat handling skills I ever saw also belonged to a racer, in this particular case a chap who had circumnavigated with clipper. Bringing a 46 footer (which, incidentally, had a bowthruster) into Newlyn he leapt off the deck onto the pontoon. ‘Oi’, shouted the skipper as the boat started drifting off, ‘you haven’t got a line in your hand’.

‘No’, said the chap, ‘I got off to, uh, check it out’.

There are various types of experience not proportional to sea miles. We went about, the skipper pinned the bow in with the thruster, and I threw the circumnavigator a line.