3mph limit at BA moorings?

[wayneakp]

... A saily backed out of his berth in front of us:

They do that Ian - but we all get along

[senator]

I could handle the in front bit, it was the straight into the side bit I was less keen on think he wished he hadn't done it though

The whole thing was witnessed by the marina manager and it wasn't me that got the ticking off. Dare say it has been told another way elsewhere though where stories of a maniac fly bridge owner will abound.

[mbird]

you made the same post last year how you put it into practise then a few weeks later you you came through Reedham with out any thought for the few boats that was moored there. Graeme

Really Graeme? I'm sorryr but I refute that accusation. I always make a point of checking how much wash I am making when passing moorings to avoid causing boats to be rubbed up and down the quay, particularly somewhere like Reedham with unforgiving concrete. I know I got told to slow down once last year through Reedham by the BA quay attendant, but at the time was only making 3.5 mph over ground against a strong ebb tide, but still no excessive wash as I recall. There is also the point many people fail to realise that sharp-bowed sea going boats tend to simply look like they are going faster than they actually are due to the shape of the bow-wave. It's a similar phenonmenon to Ford's "Kinetic design" advert campaign.

[wayneakp]

Under colregs you should have given way Ian - being still attached by his rope he was obviously restricted in his ability to manoeuvre

Oops sorry we seem to have hijacked the thread ... Now about this wash..

[mbird]

first of all you'll have to educate the idiots that there nasa (or equivelent) speed log is in knots and not mph .

Most of them can be set to kts or mph anyway. We keep ours on mph on the Broads, then change to kts as soon as we are the otherside of Mutford Lock. I do wonder why the Broads stick to the mph unit though? Is it to make it easier for hirers to judge their speed?

[Guest]

Really Graeme? I'm sorryr but I refute that accusation. I always make a point of checking how much wash I am making when passing moorings to avoid causing boats to be rubbed up and down the quay, particularly somewhere like Reedham with unforgiving concrete. I know I got told to slow down once last year through Reedham by the BA quay attendant, but at the time was only making 3.5 mph over ground against a strong ebb tide, but still no excessive wash as I recall. There is also the point many people fail to realise that sharp-bowed sea going boats tend to simply look like they are going faster than they actually are due to the shape of the bow-wave. It's a similar phenonmenon to Ford's "Kinetic design" advert campaign.

Mark it was the case the lady on the yacht behind me that was moored out side The Lord Nelson shouted to you to slow down.

All the posts all blame the boat, the tides, the wash is not excessive,how about a change of tactic and looking at the boats that are moored bobbing up and down as you pass.It works for me i will go on one engine even if it`s a strong ebb tide.

[wayneakp]

I will stand up and say that I have a lot of respect for Mark both as a skipper and a considerate person. Obviously I was not there but find it hard to believe that he intentionally caused wash of such a nature to cause distress

WAYNE

[senator]

I would definitely second that.

first of all you'll have to educate the idiots that there nasa (or equivelent) speed log is in knots and not mph . perhaps changing signs to speed in knots would help ? seems o one can judge walking speed anymore . lol ..

Even idiots can multiply by 1.15 that is if they can't work out how to press menu.

it is just unfortunate that the clever people couldn't work out that water on a tidal system moves and in different directions at different times.

The traditional method of measuring speed with a speed wheel cant compensate for this, neither can the hire boat method of engine revs =.

What both methods do do is keep wash at the intended level, something a GPS speed log doesn't.

As for Walking speed, My Nans or my athletic Sons? that would be somewhere between 2 and 5 mph which combined with a 3 knot flow could relate to a variance of -1mph to 8mph when it comes to wash generation. Its a good job we have clever people to set the rules isn't it?

As for watching the boats bobbing up and down, Horse, stable, bolt, lock and door spring to mind, that is unless you want to go round and do it again. And one engine will technically cause more wash than two at the same speed due to the correction you will have to make in order to go in a straight line.

No one should or I am sure does intentionally cause excess wash where boats are moored but likewise I have seen people getting a bit carried away with a ripple and not from my boat either. Maybe caravaning would be a better pass time for these, as long as the wind doesn't get up.

[Brigid-Mary]

I find that when im on my Rib at 6mph it makes a big wash but at 30mph it makes none at all, so does that mean 30mph is better on some boats?

Quite agree with you Barry, when I drive 'our RIB' you know the one I mean, at high speed there is minimal wash, at low speed a humungus tidal wave.

I can drive Brigid Mary along the Yare at full speed, all of 7 knots, and make a wash equivalent of a mallard on heat. The issue is not speed,in my view, but being sensible.

Broads cruisers are desinged to give minimal wash, sea going boats are not. Try approching Harwich when one of the pilot boats are about. They are not too bothered about the amount of wash they put up!!!!!!

Speed limits are a generalization, in my view. Common sense when approaching moored boats should prevail and a prudent skipper should adjust his speed to give minimal wash.

Paul

[Hockham Admiral]

Speed limits are a generalization, in my view. Common sense when approaching moored boats should prevail and a prudent skipper should adjust his speed to give minimal wash.

Paul

Well said, Paul!

The moorings at Herringfleet are a point in question... with a stiff ebb facing me and a 6mph limit I'd have to be at displacement speed to get anywhere near that limit... that would give a truly horrendous wake, but be legal...........

I find that when passing moorings if I just pull the revs back to 1200 my wake all but disappears.

[senator]

Thank's John and Paul. Just what I was trying to say in a much better way.

Forget speed over ground and set a speed through the water that creates minimal wash. If you do virtually all of the rangers will leave you alone, even if you are doing more than 4, 5 or 6 mph. It is only caravaners and speed guns that will complain.

[GrantS]

Most of them can be set to kts or mph anyway. We keep ours on mph on the Broads, then change to kts as soon as we are the otherside of Mutford Lock. I do wonder why the Broads stick to the mph unit though? Is it to make it easier for hirers to judge their speed?

I was wondering how accurate the Hire Boat Speeds are anyway, as i understood that they just used their rev counters.

So it would depend on what they were calibrated to in the first place.

I Was also wondering why the speed topic always seems to pop up from time to time ?

Not being funny, but it appears to be really bad thing if you are one or two miles an hour over the limit.

with the measurement being radar checked, (over land speed) as already mentioned, a tidal river is going to have a big influence on your speed and also the amount of wash that you make.

The wash is also a variable here, as this will depend on what type of boat / length you have and what chop is already on the river.

Regarding creating a big wash when passing moored boats, thats a no brainer really and its just courteous to slow down for a bit or just make sure that you are not going to chuck their boat about when you are passing. I don't mind a bit of wash when i,m moored up, because i'm on a boat which is on water and i expect movement.

However, i wouldn't want my boat to be violently chucked about to the point where things fall over and risk damaging my boat against the mooring. Unfortunately, not everyone does this and some will really rock you about, which we experience from time to time, but theres always the good old hand gesture to let them know you weren't happy about it. Lol.

At the end of the day, rules are rules (as they are on the highway) but why do we have this obsession with speed on here, where its almost a dark sin if you accidently cross the line.

[Soundings]

[However, i wouldn't want my boat to be violently chucked about to the point where things fall over and risk damaging my boat against the mooring./quote]

Not to mention the potential for personal injury when cooking pots etc. start flying around!

[C.Ricko]

[

I was wondering how accurate the Hire Boat Speeds are anyway, as i understood that they just used their rev counters.

So it would depend on what they were calibrated to in the first place.

:

years ago we got all our various hull types each with various engines and drove them down the river one at a time alongside the river inspector and recorded the revs at 3 and 5 mph.

[ranworthbreeze]

This rule of thumb works quite well and has been used on the Broads and canals for many years likewise the average walking speed of 4mph and the amount of wash you make on the banks.

On the narrow boats we have been on over the years the revs were, 1000 =4mph 1100=5mph, on our boat it is the same plus just under 1200 revs for 6mph. There are a few 1/4 measured mile points on the Broads, sadly the markers in some locations have seen better days , but you can use them to test your speed against revs.

Regards

Alan

[Hockham Admiral]

Alan, Hi

If you've got an Android phone there's a free app called Android Speedometer you can download (I guess there's something similar for i-phones).

Then you just need slack water and you can calibrate your revs for speed through the water very easily.... unfortunately the BA works on speed over the ground!

But again that's not a problem if you keep your phone on somewhere it can pick up the satelites and just read out your current speed over the ground.

[ranworthbreeze]

Hello John,

Thank you for that I will have a look at it.

Regards

Alan

[donnygeoff]

There are a few 1/4 measured mile points on the Broads, sadly the markers in some locations have seen better days , but you can use them to test your speed against revs.

Surely only in STILL WATER.....

As has been said before on numerous accasions, the flow of the tide will effect the speed over ground, so going one way betwwen these post will give one speed reading at 1100 revs and going the other way will give another.

I use a sat nav, cheap and chearfull one, just make sure the volume is off

[teadaemon]

Surely only in STILL WATER.....

Although still water will give slightly more accurate results (as tidal flow will vary over time somewhat), to use these to calibrate a rev counter you do two runs, one in each direction and average the results.

Before going to the trouble of doing that though, anyone who's thinking of doing this might find it worth getting hold of a laser tachometer (I think mine was about £12 on a certain Internet auction site) and using it to see how accurate your rev counter is in the first place.

[mbird]

Why would rev counter accuracy make any difference? It's only a reference point so whether it's reading 1000 revs or 1400 revs at 4mph, surely it's irrelevant

[Hockham Admiral]

You're quite correct, Mark.

Providing it reads the same every time what it reads is irrelevant...

[Guest]

is it just me or is this statement not quite right ?

As the BA chap said, "wash is subjective but speed isn't - you're either speeding or you're not".

"How can you apply a speed gun reading from a stationary position to a vessel moving with or against a tide ?"

my speedo is in MPH but doesnt register until you get to 10mph so that leaves my GPS which is in knots

but being GPS it is subject to a DOP error which is variable throughout the day, the only other alternative is

a log, perhaps a paddlewheel log for which you need to know the strength and direction of the tide so you can

add or subtract the tide speed from the indicated speed.

the boat is travelling through a moving liquid as opposed to the radar gun that is stationary so there is the

possibility for a large margin of error " are you travelling 5mph over the ground or through the water ? "

What i can say for sure is my boat can make a large wash at 3 knots if the tide is against me somewhere like Reedham

as I may be travelling through the water at 6 knots, so i'm not speeding but making a subjective wash

Or I can make very little wash at 5, 6 or more knots if I am going in the same direction

as the tide but it is often ignored that the tide direction has a huge role to play when people shout from the riverbank

or other boats to "SLOW DOWN" it's not that easy to get it right.

Rich

[ExUserGone]

Although the gps position error will change during the day the error from second to second will be very similar so speed reading over ground should be good, but if you stop it'll likely show you wandering in a star shape around your actual position.

Position error is very small these days with most units using a correction signal (egnos in europe or waas in the usa).

Still won't drop your wash against the tide though....

[quo vadis]

:yawn:its not difficult