Wash crossing

[redfastlad]

Hi,

We are planning a trip out down the Trent staring mid June and will be aiming to be in Boston around mid July ready to cross the Wash and make for the Nene, anyone else thinking about doing a similar trip??? please let me know if you are contemplating same.

[jddevel]

Seeing your post about venturing into salt water reminds me of a request on channel 16 a number of years ago when cruising between Wells-on-Sea and Kings Lynn in a force 6. An emergency call came out requesting to be on the look out for a narrowboat crossing the wash and being guided by a guy in a car using a CB radio. As the car moved in land he had lost both sight of and contact with the boat. I would imagine quite a worrying time for the narrow boat occupants. Wind and tide can be quite hairy at the best of times (we were in a twin engine 32foot cruiser) but force 6 must have been frightening for them. Didn't hear the outcome.

[Bunny]

Seeing friends Tuesday who may be interested , will ask . Bunny

[Sue]

Done properly with the wind in the right direction and preferably with Daryl the guide will see you have a very enjoyable journey.

 

Mo of NB Balmaha describes our trip in early spring 2013 perfectly..

 

A wonderful experience and if you would like to see more here is my account of the trip..

 

Enjoy

[Scholar Gypsy]

I'm getting quite excited re my trip Denver to Boston in three weeks time, weather permitting. I'll be returning (to the Nene) in August.

 

More detail of my preparations on the blog.

 

My task this weekend is to load the latest locations of the Kings Lynn buoys - they move them regularly - into the charting software... I am making less good progress with the compass, too much steel.

[Alan de Enfield]

... I am making less good progress with the compass, too much steel.

 

Easy to resolve.

 

Point the boat North (by using a compass away from the boat) and note the reading of the compass inside the boat - repeat for all of the cardinal and inter-cardinal points. You can now plot a curve for all compass headings that will show you the +/- number of degrees to add/subtract from your compass reading to get your magnetic heading - you can then add/subtract as necessary from the magnetic heading to get your true heading.

 

Read up on "swinging the compass"

 

You now have a table of compass variation

[Scholar Gypsy]

 

Easy to resolve.

 

Point the boat North (by using a compass away from the boat) and note the reading of the compass inside the boat - repeat for all of the cardinal and inter-cardinal points. You can now plot a curve for all compass headings that will show you the +/- number of degrees to add/subtract from your compass reading to get your magnetic heading - you can then add/subtract as necessary from the magnetic heading to get your true heading.

 

Read up on "swinging the compass"

 

You now have a table of compass variation

 

Thanks, yes I've read that bit of the instructions (and also the very clear and well written RYA book on navigation more generally, which tells me much more than I think I will need).

 

The problem is that I don't yet trust the hand-bearing compass I've bought, as it is not giving sensible or robust results when I am standing well away from the boat and taking a bearing for Ely Cathedral. The GPS gives COG, of course, when you are moving, and the pilot will bring his own GPS as well.

Edited May 2, 2015 by Scholar Gypsy

[Scholar Gypsy]

I've been assembling a page of useful / mad links for the Wash. Here it is - please email or PM me with any comments or suggestions for additions.

 

https://nbsg.wordpress.com/washing/

 

The other task today (the weather here in Pembrokeshire is awful) has been to load up the waypoints, and the current positions of the various buoys on the way out from Kings Lynn (they move around a bit!).

 

One of them is 1' East (0.61 nautical miles) of where the Kings Lynn Harbour Board website says it is, so that was worth checking!

Edited May 2, 2015 by Scholar Gypsy

[howardang]

 

Easy to resolve.

 

Point the boat North (by using a compass away from the boat) and note the reading of the compass inside the boat - repeat for all of the cardinal and inter-cardinal points. You can now plot a curve for all compass headings that will show you the +/- number of degrees to add/subtract from your compass reading to get your magnetic heading - you can then add/subtract as necessary from the magnetic heading to get your true heading.

 

Read up on "swinging the compass"

 

You now have a table of compass variation

Not quite true. Variation (the error caused by the Earths magnetism) can be found directly from the appropriate navigation chart. The compass error found when swinging the compass - the difference between the true heading and the compass heading - is a combination of Variation and Deviation. Take away the Variation and the result is the Deviation - the error caused specifically by the boats magnetism - which can be plotted either in table form, or better as a Deviation curve.

 

Howard

[Alan de Enfield]

Not quite true. Variation (the error caused by the Earths magnetism) can be found directly from the appropriate navigation chart. The compass error found when swinging the compass - the difference between the true heading and the compass heading - is a combination of Variation and Deviation. Take away the Variation and the result is the Deviation - the error caused specifically by the boats magnetism - which can be plotted either in table form, or better as a Deviation curve.

 

Howard

 

Correct.

 

I was just trying to do it in small steps to help someone who was perhaps not au-fait with the system.

Your way gets the same answer (deviation curve) in one step.

[Timleech]

 

Easy to resolve.

 

Point the boat North (by using a compass away from the boat) and note the reading of the compass inside the boat - repeat for all of the cardinal and inter-cardinal points. You can now plot a curve for all compass headings that will show you the +/- number of degrees to add/subtract from your compass reading to get your magnetic heading - you can then add/subtract as necessary from the magnetic heading to get your true heading.

 

Read up on "swinging the compass"

 

You now have a table of compass variation

 

Trouble is, with a steel boat and a compass with no compensation, yes you can draw up a correction chart but you may well find that some points of the compass are unuseable because the rate of correction is so great. In other words, if you try to hold a heading based on the correction chart a very small change in heading will produce a wild swing of the compass. The opposite is likely to happen at other points of the compass. Hence the use of correction spheres and magnets etc.

 

With a steel narrowboat for a short crossing I might be inclined to admit defeat and rely on a marine GPS, which can also be arranged to display compass bearing so long as you keep moving. Yes I know we shouldn't place too much reliance on these gizmos.

Either that or use a fluxgate compass with the sender unit on a longish pole.

 

Tim

[Scholar Gypsy]

 

Trouble is, with a steel boat and a compass with no compensation, yes you can draw up a correction chart but you may well find that some points of the compass are unuseable because the rate of correction is so great. In other words, if you try to hold a heading based on the correction chart a very small change in heading will produce a wild swing of the compass. The opposite is likely to happen at other points of the compass. Hence the use of correction spheres and magnets etc.

 

With a steel narrowboat for a short crossing I might be inclined to admit defeat and rely on a marine GPS, which can also be arranged to display compass bearing so long as you keep moving. Yes I know we shouldn't place too much reliance on these gizmos.

Either that or use a fluxgate compass with the sender unit on a longish pole.

 

Tim

 

Thanks Tim - my mind is moving that way. Looking at some reasonable price surface mounting compasses it does appear that their ability to correct is (as you say) limited. Fluxgate units look quite expensive, though I do have a decent mast (about 2.3 metres from memory).

 

In addition to the Mark I eyeball, my GPS, and Daryl's GPS, my final fallback is to throw one of the boys in the sea, make them swim a decent distance away from the boat, and take a bearing. We could even tow them behind us....

 

Edited May 2, 2015 by Scholar Gypsy

[howardang]

Correct.

 

I was just trying to do it in small steps to help someone who was perhaps not au-fait with the system.

Your way gets the same answer (deviation curve) in one step.

Thanks for your approval-

 

However, I suggest you re-read your last sentence. What you describe is not a table of variation. Variation is found on the chart and is only one component of the compass error, which you find when swinging a compass.

 

Howard

[Alan de Enfield]

Thanks for your approval-

 

However, I suggest you re-read your last sentence. What you describe is not a table of variation. Variation is found on the chart and is only one component of the compass error, which you find when swinging a compass.

 

Howard

 

Re-read the sentence - yes, see what you mean.

[Scholar Gypsy]

I've added quite a bit to my page of guidance for the Wash crossing.

 

I'd be grateful for any comments and suggestions.

 

https://nbsg.wordpress.com/washing/

 

I am just putting the finishing touches to my timesheet, for the segment from Kings Lynn to the Sea, and will add that shortly.

Edited May 4, 2015 by Scholar Gypsy

[cuthound]

 

Simon found that a narrowboat was not ideally suited as a water ski tow boat

[redfastlad]

Thanks for all your comments, the plan originally was for me to call up my old mate Norman Parnell from Drove End at Gedney, he looks after the RAF Holbeach bombing range. Norman has a small boat that he services the marker bouys and navigation beacons with, I have been quite a way out into the wash with him in his JCB he does have a really in depth knowledge of the wash and is a well known celeb in those parts.Should Norman be unavailable we will pre book the pilot,so at the moment it is all systems go with two guys helping myself I am looking forward to the challenge.

[Alan de Enfield]

........... I have been quite a way out into the wash with him in his JCB he does have a really in depth knowledge of the wash and is a well known celeb in those parts..........

 

He drives a JCB across the Wash ?

 

King John tried driving across the Wash and lost the crown jewels.

[redfastlad]

Yes we went out, its not that deep way out from the shore, not that far but close enough to watch the coasters coming in to Sutton bridge

[Scholar Gypsy]

Thanks for all your comments, the plan originally was for me to call up my old mate Norman Parnell from Drove End at Gedney, he looks after the RAF Holbeach bombing range. Norman has a small boat that he services the marker bouys and navigation beacons with, I have been quite a way out into the wash with him in his JCB he does have a really in depth knowledge of the wash and is a well known celeb in those parts.Should Norman be unavailable we will pre book the pilot,so at the moment it is all systems go with two guys helping myself I am looking forward to the challenge.

 

I'd be really interested if Norman could point me to the locations of the buoys on the approach to the Nene. I've found this chart, but (to program them into my GPS) I would quite like the lat and long.

 

Many thanks!

[by'eck]

Might be worth trying a trick used by our forefathers. After the West Indies was discovered navigators had trouble finding Barbados when returning upwind from the windward islands, following lots of tacking. Folklore has it they would throw a pig overboard and see which way it swam. Their excellent sense of smell (and self preservation ) had them sniff out the land from downwind and swim towards it.

Not saying it would work in the Wash but maybe worth a try

[howardang]

 

I'd be really interested if Norman could point me to the locations of the buoys on the approach to the Nene. I've found this chart, but (to program them into my GPS) I would quite like the lat and long.

 

Many thanks!

The best way to get the up to date co-ordinates of the buoyage would be to buy the up to date chart and take them from there. The chart should be on board your boat during the passage in any case.

 

Howard

[Scholar Gypsy]

The best way to get the up to date co-ordinates of the buoyage would be to buy the up to date chart and take them from there. The chart should be on board your boat during the passage in any case.

 

Howard

 

Er, for both the Kings Lynn and the Wisbech approaches there is a section of the route where the buoys move frequently and are not marked on printed & published charts (eg Imrays, where I have the latest Nov 2014 edition).

 

The latest Lynn chart from the HM is here (just over a week old), and the exact positions are here (with one error, that will be corrected shortly).

 

Ideally I would like to find the equivalent position data for the route into Wisbech, although that looks a bit more straightforward (but the penalty for getting it wrong is being shot at by the RAF....).

 

I probably won't need any of this of course - Daryl the guide knows his way around - but I am just enjoying my researches....

[Naughty Cal]

The best way to get the up to date co-ordinates of the buoyage would be to buy the up to date chart and take them from there. The chart should be on board your boat during the passage in any case.

 

Howard

They will already be out of date for the Wash.

 

The buoys move so often.

 

Best to get the latest positions from the port authority website a couple of days before setting off.

[shipsbiscuit]

 

I'd be really interested if Norman could point me to the locations of the buoys on the approach to the Nene. I've found this chart, but (to program them into my GPS) I would quite like the lat and long.

 

Many thanks!

 

Hi,

 

Wisbech Yacht Harbour has an A4 sheet grandly titled 'Port of Wisbech List of Lights and Beacons'. A Jan 13 version was pinned up on the pontoons when I last set off from there (August 13) and I snapped a pic of it for the unlikely event I needed the lat/longs so I could dig that out for you if you want.

 

You can usually, though not always, see from one buoy to the next in the main channels and a rough bearing off the chart is often enough to sort things if not... no harm in researching and plotting these things but I'd not worry too much if you don't have them.