When and Where to See the Trent Aegir: A Complete Guide
More about the Trent Aegir can be found on this page
TAKE CARE
The River Trent has steep banks – ensure that you take care of your personal safety and donot take risks trying to get a good view.
The Trent Aegir, also known as the Eagre, is a tidal bore on the River Trent. At certain times of the year, it is possible to see a bore of up to five feet high.
The Aegir occurs when a high spring tide meets the downstream flow of the river forcing it back and causing a wave to flow upstream. Typically it is possible to see the bore from Derrythorpe to as far up the river as Gainsborough. Beyond Gainsborough the bore is reduced to a ripple.
The best places to see the Aegir are at Gainsborough, Morton, East Stockwith, West Stockwith, and Owston Ferry.
The appearance of a bore can be affected by various other factors that may enhance or detract from the size of the bore;
- excessive flood water flowing down the river will reduce the size of the bore
- too little water flowing down the river will also reduce the size of the Aegir
- depending on the wind direction winds may enhance or detract from the size of the Aegir
- lighting may also affect how the Aegir is perceived – in my experience, it looks best when the sun is behind the river
- depending on the weather conditions the Aegir can be up to 30 minutes earlier than predicted.
To help me improve my predictions I should be grateful if you could email me (angus@townley.com) with details of actual times and appearances of the Aegir. Don’t forget to say where you were. Many thanks.
Also please feel free to share photos and reports of the aegir below.
BEAR in mind that these are predictions and natural phenomena do not work to an exact timetable and for the reasons listed above the Aegir can arrive up to 30 minutes earlier than predicted. Be early to increase your chances of seeing it.
How are these calculated?
The forecast uses the approach that the Environment Agency used to use.
As I can only get annual data for Keadby the predictions are based using tide times at Keadby.
- River Trent Aegir Predictions
- From the River Trent tidal predictions, when they are published:
- Use KEADBY levels. Metres AOD
- Use Gainsborough times, GMT
- If Gainsborough time is not available, an estimate can be calculated by taking the Keadby time and adding 1h 05m +/- 5mins
- Aegir time is GMT time at Gainsborough minus 2 hours eg. 21:00 high tide = 19:00 Aegir prediction.
- Prospect predictions:
- Small 4.50 to 4.69 metres AOD *
- Medium 4.70 to 4.89 metres AOD **
- Large 4.90 to 5.09 metres AOD ***
- Extra Large 5.10 to 5.30 metres AOD ****
- 5 Star 5.40 metres AOD and above. *****
If you are interested: I use a power query routine in excel to read the data from the tide tables and to calculate the forecasts.
1920 at Jenny Hurn tonight. Could definitely see it coming by the way the reflections changed, but not as much as at the end of March. Also heard my first cuckoo of the year!
Thanks for the report. I heard my first cuckoo today too!
I was at East Ferry on the 27th. Heard a cuckoo too so nice to have confirmation. The tide came in with a gradual rising.
The Aegir reached the Jenny Hurn pumping station tonight at 18:46. Just a sort of swelling mid-channel but a lot of dramatic sloshing round the mud banks. We went on up to East Stockwith where we just saw some twigs changing direction and a couple of very disappointed surfers, who said it was breaking a foot high at the motorway bridge but they couldn’t get in the water in time.
Thanks Jennifer. I saw it at the M180, when it was breaking, but by the time it was in West Butterwick, it was just a swell. It just seemed to leave energy the further upstream it went.
Thanks for posting these. I have now moved to Gainsborough not JUST to see the Aegir, but hopefully this will increase my chances a little. I suspect for the early March 4*s it will be too dark to see it, unless it does its “30 minutes early” trick. Hoping to get to the late March ones!
Hi Jennifer. Its a great sight when it decides to show. Just not be very good for the last few years. I took several videos in 2019, when it was good.
Hi Angus, Can I just double check if the times are GMT or BST, because the 4* predicted on 30th March is the days the clocks go forward, so it’s kind of crucial!
Hi Jennifer,
The tide tables I use are adjusted for BST so the times provided are GMT or BST depending on when they refer to.
I guess I should make that clearer on the table.
Thanks
Angus
Hi Angus,
I was supposed to go to Gainsborough this morning to hopefully see the predicted 4 star Aegir.
In the end I decided not go, but wondered whether anyone checked it out?
I did read that the following on the gov UK site that: ”
*”River levels are forecast to rise at the Keadby river
gauge as a result of high spring tides coinciding with high river levels. Consequently, flooding of roads and farmland is possible this morning, 19/09/2024 and
tomorrow morning, 20/09/2024.”*
It sounds to me by that, that the Aigir would have been a ‘no show’, but did anyone manage to see?
Hi, a no show again on 9th and 10th April 2024, watched for half hour before untill tide incoming, at Morton. Someone says dredging further down river can affect it?
Hi Angus
No show of our aiger last night,but I notice the river Severn had a good bore last night
Any thoughts on why the seven would get one and not us
Hi John,
I went to the M180 Bridge and just watched the river languidly change direction so did not try to follow it any further. Possibly the extra water in the river worked against it. I don’t know why the Severn always gets a good Bore. I am hoping that we should see some good Aegirs this year but based on last night’s effort – maybe not!
For the Severn, the 2 affecters of wind and river flow tend to affect timing rather than whether it exists. A downstream wind tends to delay the Bore’s arrival and can make the face a bit steeper. Also, a high volume of river flow will delay the arrival of the wave, but I’ve never worked out if the wave is bigger or smaller. A massive effect is a deep low pressure over the estuary, so to see a good bore, you want really bad weather during an Equinoxial Spring tide, and in the main, in the PM.
Thanks for the information. I have a copy of Rowbotham’s book on The Severn Bore and he lists a number of factors that can affect both timing and appearance.
The Aegir seems a lot more capricious. In 2019 I was able to get images of some very good Aegirs (you can see pictures and videos on the website) – mainly in the morning but since then they have not been so good. I’ve been wondering about the impact of weather fronts. There is also a cycle of tides that lasts There is some information here https://ntslf.org/about-tides/tidal-river-bores
Did anyone go and see last nights 5star 12 2 24 aiger I was hopeing someone would have posted a comment by now
Went along on the 12th Whitton Gardens arrived about 1930 stopped till 2015 .Nothing really happened water slowed up but that was it .To much water flowing downstream from weekend heavy rain .Maybe better conditions in march.
Just posted new timetable up on sites in Gainsborough with referencing you Angus.
Hi Angus – is your method for calculating published anywhere or would you be willing to share? I was thinking I could automate this for you? We could perhaps even combine it with other factors so you get a ‘live’ update as to how good the aegir might be?
Thanks,
Paul
Hi Paul. Yes I can share. I have automated it myself using PowerBI. I have already sorted 2024 data just not published yet – I’ve had others things to do.
It would be great to be able to build a model including live factors such as flood water in the river and wind direction etc. It was in teh back of my mind when trying to sort out a model and why I spent most of 2019 trying to see all aegirs small or large and adjacent tides. But did not really come to a conclusion.
The September 3rd 4* Aegir passed the Morton bend at c.08:50 so about 20 minutes ahead of the Gainsborough forecast. Getting there 30 minutes before, however, I managed to see my first ever bore so thank you so much for posting! As my first bore, I cannot benchmark it first hand but, although definitely visible, it was tame compared to You Tube clips. Nonetheless an incredible sight – also for the swell and fall of the river afterwards and the gentle sounds throughout. I hope it won’t be my last! Thank you!
The September 4th Aegir passed the Morton bend just north of Gainsborough at c.08:50 so about 23 minutes ahead of forecast. Getting there 30 minutes before, however, I managed to see me first ever bore so thank you so much for posting! As my first bore, I cannot benchmark it first hand but, although definitely visible, it was tame compared to You Tube clips. Nonetheless an incredible sight – also for the swell and fall of the river afterwards and the gentle sounds throughout. I hope it won’t be my last! Thank you!
APOLOGIES – I PUT THE WRONG DATE! = please see below:
The September 3rd 4* Aegir passed the Morton bend at c.08:50 so about 20 minutes ahead of the Gainsborough forecast. Getting there 30 minutes before, however, I managed to see my first ever bore so thank you so much for posting! As my first bore, I cannot benchmark it first hand but, although definitely visible, it was tame compared to You Tube clips. Nonetheless an incredible sight – also for the swell and fall of the river afterwards and the gentle sounds throughout. I hope it won’t be my last! Thank you!
APOLOGIES – I PUT THE WRONG DATE! = please see next post
I came to see the 4* on Sunday morning at the bend by the Jenny Hurn pumping station. Just as I was thinking it was about due, a lady came up to her garden gate and asked if I was waiting for the Eagre. As I was asking her if she’d seen it the day before, there was a slosh and a gurgle under my feet. I might have seen the back view of the bore if I’d looked off to my left but was transfixed by the gurglings below me, and when I looked up realised the river was flowing back the other way.
So I can sort of say I saw it!
Arrived at Morton at 7:30pm this evening and had missed it by five minutes ☹️
Can someone tell me what the stars mean on the timings in the chart please? Thank you
Hi he stars are based on the high tide at Keadby and are meant to be an indication of the strength of the Aegir.
Friday 4th August travelled from South Notts to Gainsborough hoping to see 3 star event. Not even a ripple. The River changed direction and the level came up slowly with no show.
Keep persevering.
Hi Angus, Hope you are well. I trust you don’t mind me pointing out the August 31, one star Aegir, is showing a 9.12 m tide at Keadby. I think it should maybe read 4.12m.
I am going to try and see the Aegir early August, Sept. & Oct. at West Stockwith or Gainsborough. I have now been to about five over the last say 15 years – three were a total damp squib – all four stars, btw – the other two good (3*, 30 Sept. 2015) to excellent (4*, 29 Sept, 2011).
Kind regards,
David (NE Derbyshire)
Yes – I know from experience! Looking at images of the Severn Bore yesterday -it does not look to have been particularly impressive.
Thanks again Angus for doing these. Not yet sure if anyone saw the 4* earlier tonight but I have put links up to the 2023 Predictions in Gainsborough.
23/3/23 No show of aiger tonight was with a man who had come from skegness who wanted to see his first aiger we waited near E ferry till
6.30ish but nothing,got to wait while September now
John
Did you see the flow change direction? Unfortunately I was not able to get out last night.
Yes we saw the flow change direction
Angus
John
Unfortunately, that’s the nature of the beast!
Tides can be very late and very early…. Often +\- 10-20mins even occasionally 30-40mins!!!! But a tide will always change and be visible in the turning direction of the flow.
Sounds like they missed it, looks like the river was too full anyway for anything spectacular!
Yes – I know from experience! Looking at images of the Severn Bore yesterday -it does not look to have been particularly impressive.
Anyone one have any experience of what would be classified as “too much water in the river”? Prolonged high levels I guess would also scour/deepen the river channels….
I was thinking maybe around 1m at Gainsborough? It’s 2.4m at the moment which IMO would be way too much. Being half the tidal height it would swamp any form of a Aegir.
Another impact on tide height is atmospheric pressure known as the “Inverse Barometer Effect”. https://www.swellnet.com/news/swellnet-analysis/2016/04/19/inverse-barometer-effect
Indeed, air pressures can have a significant effect on tides. A low offshore the estuary can really boost the power of a tide. I was at the Arnside last month, one day the tide was powerful with a low out to sea, the next day same size tide with a high out to sea and the bore was half the size and power. I heard the high and strong northerlies made the Severn over 30mins late at its point of origin which is unheard of! Hoping to come up to the Trent this month, but only if we get the right conditions.
Interesting article about ‘Super Tides’ from the Met Office published in 2014.
It would suggest that there is a 4.5-year cycle – so 2019 would have been the next year for ‘Super Tides’ after 2015 and may explain why the last 2 years were not good for Aegirs. https://blog.metoffice.gov.uk/2015/09/24/super-tides-this-autumn/
Very happy to see these up again for this year, thanks for doing it. Can you possibly clarify the dates/times at the beginning of August and September, as it looks like the evening times are shown before the morning ones, so I’m not sure if it means the next morning, or the night before? Hoping to trek over from Staffordshire at some point!
Thanks for spotting that – the table in excel was doing its own sort! I’ve now made it show correctly.