Bow thrusters and mooring buoys

[Chiara’s slave]

As the saying goes, "Different ships, different long splices"

Sailing my old Prout cat singlehanded I found the easiest way to secure to a big mooring buoy with just a ring was to gently nudge the buoy under the bridgedeck then lean over the bow and attach a temporary line with snap hook before setting up my bridle.

We do exactly that, but replace ‘bridgedeck’ with ‘front beam’.

 

[capnsensible]

Perhaps more than spliced eye mooring rope issues you get agitated about

PS If you read post #1 you will see this had surprised me as not seen before

So why is it such a problem then?

 

[Poignard]

May I draw the attention of anyone who just likes to do things the easy way, to the two genuine 'Moorfast' Mooring Aids/ Line Threaders I am currently offering for sale at a ridiculously low price on the 'For Sale' forum?

 

[dunedin]

So why is it such a problem then?

Why don’t you think about it then? If a boat has got close to a mooring buoy but a metre too far to port of the buoy, so presses bow thruster then it sucks in water - and the pick up line - from the starboard side.
Boat then moored by bow thruster blades. Cue RNLI call-out to release, and cut pick-up rope. Suspect lift also to check/repair bow thruster.

 

[capnsensible]

Why don’t you think about it then? If a boat has got close to a mooring buoy but a metre too far to port of the buoy, so presses bow thruster then it sucks in water - and the pick up line - from the starboard side.
Boat then moored by bow thruster blades. Cue RNLI call-out to release, and cut pick-up rope. Suspect lift also to check/repair bow thruster.

So it's happened......once. Someone made a mistake. Oh dear.

 

[johnalison]

On a more sinister note, have swimmers been sucked into these whirring dervishes and nastily injured? Ships have warning signs on theirs but I don’t remember seeing them on yachts.

 

[xyachtdave]

Bow thrusters are an embarrassment on anything under 36ft. I've witnessed an apparently 'amazing dinghy sailor' using his bow thruster to tack his Southerly cruiser under sail.

Having said that, crewing on a big 55ft X with the drop out the bottom of the boat thruster complete with beeping warnings that it's been deployed isn't great either.

Ban them.

 

[srm]

I've witnessed an apparently 'amazing dinghy sailor' using his bow thruster to tack his Southerly cruiser under sail.

Probably a good move to save the embarrassment of getting stuck in irons, especially if in a narrow channel. (or am I the only one here to have miss judged making a tack) However, if the boat had sufficient way on to tack properly the bow thruster would have very little or no effect.
Have chuckled a number of times when hearing a bow thruster grinding away through a sharp turn in a marina. At the speed the boat was going the rudder was providing all the turning force.

 

[B27]

Probably a good move to save the embarrassment of getting stuck in irons, especially if in a narrow channel. (or am I the only one here to have miss judged making a tack) However, if the boat had sufficient way on to tack properly the bow thruster would have very little or no effect.
Have chuckled a number of times when hearing a bow thruster grinding away through a sharp turn in a marina. At the speed the boat was going the rudder was providing all the turning force.

Using a thruster as well as the rudder might be a handy way to move the boat diagonally more than rotate it?
If you're going to lumber the boat with drag-tastic hole in the bow, you might as well make the best of it.

It's good to practise with the tools you have.
I don't have a thruster, but then I'm too miserly to go near marinas anyway.

 

[westhinder]

…
Have chuckled a number of times when hearing a bow thruster grinding away through a sharp turn in a marina. At the speed the boat was going the rudder was providing all the turning force.

A surprising number of people seem use their bow thruster to steer the boat in a marina, as if they had no rudder.
Good skippers steer almost exclusively with the rudder and make final adjustments with the thruster, even in confined spaces.

 

[srm]

Using a thruster as well as the rudder might be a handy way to move the boat diagonally more than rotate it?
If you're going to lumber the boat with drag-tastic hole in the bow, you might as well make the best of it.

Very few people seem to understand that a flow of water across the thruster tunnel reduces its effectiveness. Perhaps visualise the water flow from the thruster getting left behind as the boat moves forward. A thruster is most effective when the vessel is effectively stopped in the water. As speed increases so the thruster becomes less effective. By the time a boat has enough steerage way to make a right angled turn using the rudder the thruster has no significant effect, hence my chuckling at the pointless grinding of thrusters.

It is a great tool for pushing the bow one way or another at very slow speed ahead or astern while getting in or out of a berth, (or recovering a seismic cable) but is not a second rudder when the boat has steerage way.

 

[Tranona]

On a more sinister note, have swimmers been sucked into these whirring dervishes and nastily injured? Ships have warning signs on theirs but I don’t remember seeing them on yachts.

a sticker does cme with the thruster but don't think anybody bothers/ The typical tunnel is 125mm diameter so difficult to imagine both why a swimmer would get that close to one that is in use let alone put a body part in the tunnel. The warnings on ships is because they do put out enough flow of water to affect objects close by. Have a look at the thruster on the Condor ferry when it leaves its berth in Poole against a brisk southerly.

 

[capnsensible]

A great tool for those that moan how their long keel yachts are difficult in marinas.

 

[Adjag]

On yachts with stern scoops often easier with small crew to back up to the buoy for a simple way of catching it -often seen in med but maybe not a uk approach.

Yes we often do that (especially if I'm onmy own) Usually rig a long line from the bow cleat then walk it forward (after passing through the body strop or eye)

 

[mrangry]

I must admit that I have considered fitting a thruster to assist in maria berthing in windy conditions, however cant justify the cost.

I did see the article and just wondered why the crew didnt just cut the pick up line and reimburse the cost of its replacement to North Ayrshire Council rather than ask for RNLI assistance.

Lifeboat and coastguard teams race to help yacht in difficulty in Millport Bay

https://rnli.org/news-and-media/2024/july/19/largs-rnli-launch-to-vessel-in-distress

 

[boomerangben]

A couple of thoughts. Clearly when picking up a mooring approaching bow downwind in astern affords the helm a good view and the opportunity to execute the manoeuvre single handed, but you could still pick up the buoy amidships or even closer to the bow with a competent crew.

Bow thrusters, don’t have one, but can’t help feeling that as boats get bigger and marinas more densely populated, bow thrusters might become more the norm and indeed expected…….. cue the conversation with the marina manager “I need a different berth because the current one is too tight…” “ we assume that boats have a bow thruster these days…”. But they do sound horrible - to me they sound as if something expensive is grinding itself to bits.

 

[dunedin]

I must admit that I have considered fitting a thruster to assist in maria berthing in windy conditions, however cant justify the cost.

I did see the article and just wondered why the crew didnt just cut the pick up line and reimburse the cost of its replacement to North Ayrshire Council rather than ask for RNLI assistance.

Lifeboat and coastguard teams race to help yacht in difficulty in Millport Bay

https://rnli.org/news-and-media/2024/july/19/largs-rnli-launch-to-vessel-in-distress

Think the boat was singlehanded - and the RNLI crew couldn’t cut without going into the water.

Bow thrusters are generally great for marinas - but dim approach for moorings with pickup lines

 

[Chiara’s slave]

A couple of thoughts. Clearly when picking up a mooring approaching bow downwind in astern affords the helm a good view and the opportunity to execute the manoeuvre single handed, but you could still pick up the buoy amidships or even closer to the bow with a competent crew.

Bow thrusters, don’t have one, but can’t help feeling that as boats get bigger and marinas more densely populated, bow thrusters might become more the norm and indeed expected…….. cue the conversation with the marina manager “I need a different berth because the current one is too tight…” “ we assume that boats have a bow thruster these days…”. But they do sound horrible - to me they sound as if something expensive is grinding itself to bits.

The sound is like an in sink waste disposal thing. Or a cavitating outboard.

 

[oldmanofthehills]

A great tool for those that moan how their long keel yachts are difficult in marinas.

Bow thrusters might be an excellent idea if the cost of the conversion wasnt about as much as we paid for yacht, and if there was actually anywhere to instal it on our tiny LM27.

We simply say "Long keeler - Keep well back" or words to that effect, and always go in forward towards the pinch point. Only ever hit pontoon one hose reel

 

[B27]

I must admit that I have considered fitting a thruster to assist in maria berthing in windy conditions, however cant justify the cost.

I did see the article and just wondered why the crew didnt just cut the pick up line and reimburse the cost of its replacement to North Ayrshire Council rather than ask for RNLI assistance.

Lifeboat and coastguard teams race to help yacht in difficulty in Millport Bay

https://rnli.org/news-and-media/2024/july/19/largs-rnli-launch-to-vessel-in-distress

'People don't generally 'call for RNLI assistance', they let the coastguard know they have a problem, the coastguard tasks the RNLI if they see fit.

"Michael Holcombe, helm at Largs RNLI, said: ‘The casualty vessel made the right decision to call for help when they realised they were in difficulties."
I will take his word for that.