Tidal Range - Great Yarmouth Bridges.

[Paul]

Can anyone point me towards a difinitve guide / calculator for the actual range at Great Yarmouth? I know Norfolk-Broads.org's tide tables gives the estimated range at Gorleston which whilst not absolutely accurate for the Bure Bridges is a good indicator of the likely level of low water compared to the "mean" value, but what is that?

I've always calculated it as six feet, and I think HW in there handbooks suggest it could be as much as two meters, six feet six inches, but what is the average, and what is the lowest. I've never had to bother too much before, about the biggest I've ever taken through so far is 8'6 which clears easily but what about something taller, say just for example, 11'4 with arches folded. The height given for mean high water is 6'9, suggesting a low water clearance well in excess of the 11'4 needed, but are there low water clearances at Yarmouth which are ever below that?

[MauriceMynah]

I believe that there cannot be a "definitive" guide  on this as there are too many variables. Atmospheric pressure and wind direction to name but two.

[Meantime]

15 minutes ago, Paul said:

Can anyone point me towards a difinitve guide / calculator for the actual range at Great Yarmouth? I know Norfolk-Broads.org's tide tables gives the estimated range at Gorleston which whilst not absolutely accurate for the Bure Bridges is a good indicator of the likely level of low water compared to the "mean" value, but what is that?

I've always calculated it as six feet, and I think HW in there handbooks suggest it could be as much as two meters, six feet six inches, but what is the average, and what is the lowest. I've never had to bother too much before, about the biggest I've ever taken through so far is 8'6 which clears easily but what about something taller, say just for example, 11'4 with arches folded. The height given for mean high water is 6'9, suggesting a low water clearance well in excess of the 11'4 needed, but are there low water clearances at Yarmouth which are ever below that?

I'm not sure there is any real definitive guide. The following gauge maybe of some help it is on the coast at Yarmouth. Between the highest and lowest low water in the last five days there has been about a meter which could make a lot of difference at the bridges. Also on the 31st March there was barely 0.8m between low and high, whereas the last tide there has been about 1.8m. I would suggest you look at when springs are as the low is likely to be lower then.

https://flood-warning-information.service.gov.uk/station/6015?direction=u

[grendel]

maybe once it is again open the yacht station could give you a better indication.

[ranworthbreeze]

I always use the Broads Authority tide tables, these give you the height of low water. From these I calculate if a passage through the Yarmouth bridges and back again is possible. Our air draft with everything down is 9 foot 8 inches so in effect we are looking at 10 foot. A low water height of .014 meters or less will allow for 10 foot clearance.

We have found that at the yacht station if you can see 7 rungs out water on the ladders there is a minimum of 10 foot at the bridges below. As always the bridge markers are never clear on the lower markings and there is not too many to check out in either direction.

Regards

Alan