Southampton to Brighton Marina - Navionics Tidal Streams?

[JakeMM]

Hi,

I'm currently planning to bring a sailing yacht from Southampton to Brighton Marina.

I will be having someone experienced on board to help me, and will properly plan the passage nearer the time, but as an early step (and a feasibility study) - I was just trying to get a rough idea as to timings, tidal streams etc.

1) Does Navionics on an iPad display tidal streams in advance, and plan passage times accordingly? For example, can I set this to "18th July", and then play around with different departure times and see how this affects the total journey time?

2) I've confirmed that my berth in Southampton is accessible at any state of the tide. Brighton Marina have also finished their recent dredging operation, so I believe I will have access to Brighton at any state of the tide (but will confirm this with them as I need 1.5m draft).

The passage seems to be 55nm, and I'm expecting a cruising speed of 5 knots. I'm prepared to use the engine for the whole trip if necessary - should the winds be coming from the East. Without tidal streams, this works out at 11 hours.

But obviously the tidal streams will have a major impact on this.

Thanks

 

[Refueler]

Best laid plans and all that ....

I delivered my Snap 23 to Brighton from Langstone years ago ... we ended up literally on fumes in the outboard tank for final entry. What with lack of wind ... lobster pots / fishing long lines and so on destroying the course planned ...

Once I get to my other PC .. I'll see if I can rustle up the ADM Tidal stream atlas for you ...

 

[andrewbarker]

Hi,

I'm currently planning to bring a sailing yacht from Southampton to Brighton Marina.

I will be having someone experienced on board to help me, and will properly plan the passage nearer the time, but as an early step (and a feasibility study) - I was just trying to get a rough idea as to timings, tidal streams etc.

1) Does Navionics on an iPad display tidal streams in advance, and plan passage times accordingly? For example, can I set this to "18th July", and then play around with different departure times and see how this affects the total journey time?

2) I've confirmed that my berth in Southampton is accessible at any state of the tide. Brighton Marina have also finished their recent dredging operation, so I believe I will have access to Brighton at any state of the tide (but will confirm this with them as I need 1.5m draft).

The passage seems to be 55nm, and I'm expecting a cruising speed of 5 knots. I'm prepared to use the engine for the whole trip if necessary - should the winds be coming from the East. Without tidal streams, this works out at 11 hours.

But obviously the tidal streams will have a major impact on this.

Thanks

As far as I remember, if you leave Southampton around 6 hrs before HW Dover, you will have a fair tide all the way. The only real headaches are the submerged barrier east of Portsmouth and the passage past Selsey Bill. I hope you also have a moderate westerly or southerly wind to help you along.

 

[johnalison]

The streams in the Solent are stronger than nearer Brighton so it is not the end of the world if you feel like dawdling and end up a bit late. With shallow depths being reported in Brighton it is more important to get there well away from low tide.

 

[alexincornwall]

1) Does Navionics on an iPad display tidal streams in advance, and plan passage times accordingly? For example, can I set this to "18th July", and then play around with different departure times and see how this affects the total journey time?

No. You can use Navionics to work out the tidal stream times, speed and direction for any given day, but you can't use the app to predict your route time for a date in the future. Neither does it take into account any tidal streams when using the auto route function (which I would use with extreme caution; it's a planning tool and I wouldn't recommend navigating by it).

You'll only really have any interest in East and West going tide so just tot up all of the east and all the west over the 11 hours, and note the difference between them. You can then work out how much tide is going to help or hinder you. In reality, I suspect it will equate to pretty much nothing over an 11 hour passage.

2) I've confirmed that my berth in Southampton is accessible at any state of the tide. Brighton Marina have also finished their recent dredging operation, so I believe I will have access to Brighton at any state of the tide (but will confirm this with them as I need 1.5m draft).

Navionics shows an area of chart datum just outside the dredged area of 0.8M. You need 1.5M and I'd be inclined to add a cautious 1M for safety. That means you need a height of tide no less than 1.7M. If the 18th is your anticipated arrival day then you will need to get in before 1100, after 1320, or before 2345. Stick between those timings and you'll be in with no issues.

If you're a pocket technology sort of a person (like me), I'd recommend downloading the Imray Tides Planner app also.

 

[XDC]

Acshually Alex my Navionics app gives me three days into the future ... not what the OP wants ... just for info ?

 

[alexincornwall]

Acshually Alex my Navionics app gives me three days into the future ... not what the OP wants ... just for info ?

View attachment 117694

Sorry, that's not what I meant. My Navionics actually gives me the info you've posted for 5 years into the future so I'm not sure why you only get 3 days? What I meant was the app won't take the affect of a fair or foul tide into it's arithmetics when calculating the length of the route, which I understood to be the OPs question. It does a simple distance/speed equation and that's as advanced as it gets... I think.

 

[Refueler]

Sorry, that's not what I meant. My Navionics actually gives me the info you've posted for 5 years into the future so I'm not sure why you only get 3 days? What I meant was the app won't take the affect of a fair or foul tide into it's arithmetics when calculating the length of the route, which I understood to be the OPs question. It does a simple distance/speed equation and that's as advanced as it gets... I think.

Tidal stream / current doesn't change 'length of route' - that's fixed as in this guys case 55nm. So I'm a little lost in your last part ..

 

[alexincornwall]

Tidal stream / current doesn't change 'length of route' - that's fixed as in this guys case 55nm. So I'm a little lost in your last part ..

Agreed, a typo in my haste which should have read duration. Tidal stream would affect SOG, the only other vital component in calculating passage time.

 

[Refueler]

Agreed, a typo in my haste which should have read duration. Tidal stream would affect SOG, the only other vital component in calculating passage time.

And tidal stream will affect the distance travelled through water .... may sound a simple fact - but surprising how many forget it. The boat will still do its normal speed through water ...

 

[LadyInBed]

What you need to get fixed in your mind is that in the central English Channel area the tide turns at about H/L Water Dover.
And
On Springs (full and new moon) HW Dover is around midday / midnight so the tide turns East to West.
On Neaps LW Dover is around midday / midnight so the tide turns West to East.

All you have to do is look at the moon ??

 

[Nina Lucia]

try savvy navvy app

 

[laika]

You'll only really have any interest in East and West going tide so just tot up all of the east and all the west over the 11 hours, and note the difference between them. You can then work out how much tide is going to help or hinder you. In reality, I suspect it will equate to pretty much nothing over an 11 hour passage.

I respectfully disagree. As johnalison points out, the tidal flow is not consistent across the whole trip. Moreover, with the wind on your side you should be able to have tide with you most of the way. Get to the bottom of southampton water (current in your favour) 3 hours after hw portsmouth, stick close to the north shore (while the tide is still going the other way in the middle) and neptune willing you should have tide with you most of the way and arrive at Brighton with plenty of water.

Normally I'd say to factor in the fact that bad luck will often intervene to put you on a dead run from selsey to brighton requiring a couple of gybes but as the OP is OK with motoring this shouldn't be an issue.

The official word from Brighton marina is still to avoid entry 2 hours either side of LW. Dredging is ongoing and the visitors' pontoons are all out. They couldn't tell me when the entrance would be done but it seems to be some time later next month and it'll be a bit after that that they have it surveyed to allow them to tell people the official depths.

Call me old fashioned but tidal stream atlases for the solent and the channel are essential purchases for anyone who sails here for more than a season (and a copy of the heinously-expensive-for-what-it-is "winning tides" for anyone who even cruises regularly in the solent). The tables in Reeds are ok for most of the channel but don't have the detail for the solent

 

[Refueler]

When I sailed the Solent / EC region .. I had the Adm Tidal Streams hourly 'maps' scanned and geo-referenced in Seaclear. If anyone uses OpenCPN / Seaclear or similar open style PC chart plotter where scans can be referenced and used - then this can be a great tool.
I could flick in a sec from tidal 'map' to chart - with GPS position shown in them ... all I had to do was watch the time and call up the correct 'map' ....

 

[captain webb]

What you need to get fixed in your mind is that in the central English Channel area the tide turns at about H/L Water Dover.
And
On Springs (full and new moon) HW Dover is around midday / midnight so the tide turns East to West.
On Neaps LW Dover is around midday / midnight so the tide turns West to East.

All you have to do is look at the moon ??

Looking to swim a part of the sea around here. Would you be able to offer some advice?

 

[LadyInBed]

Looking to swim a part of the sea around here. Would you be able to offer some advice?

No!

 

[Stemar]

The only real headaches are the submerged barrier east of Portsmouth and the passage past Selsey Bill.

The barrier isn't really a problem. Just take the passage in the middle. There is an inshore one, but I've never used it and understand it's a bit shallow. Actually, with any decent amount of tide, you could probably go straight over the barrier. I have, but I draw change from a metre, and I didn't put my full weight down as we went over, so not recommended for a deep keel!

As for Selsey, no real problems as long as you follow the buoys and keep your eyes peeled for pot markers. It does seem to be a rule that the more in your way they are, the more invisible the markers

 

[Refueler]

The barrier isn't really a problem. Just take the passage in the middle. There is an inshore one, but I've never used it and understand it's a bit shallow. Actually, with any decent amount of tide, you could probably go straight over the barrier. I have, but I draw change from a metre, and I didn't put my full weight down as we went over, so not recommended for a deep keel!

As for Selsey, no real problems as long as you follow the buoys and keep your eyes peeled for pot markers. It does seem to be a rule that the more in your way they are, the more invisible the markers

A few boats have struck keels on that barrier ... few years back - there was a French Race Boat that lost the keel to it - on way to refit !!

I used the inshore gap quite often with my boat - but like you - is a shade under 1m draft. Only once did I find that wind / current caused her to veer towards the pier .. unexpected !

 

[TernVI]

If the tide's with you, why would you be going through the barrier?
More of that favourable tide further out beyond the fort.
You want to get offshore to clear the shallows around Langstone and Chi Harbour entrances anyway.

 

[Refueler]

If the tide's with you, why would you be going through the barrier?
More of that favourable tide further out beyond the fort.
You want to get offshore to clear the shallows around Langstone and Chi Harbour entrances anyway.

My post was in reply to another who mentioned the inner passage ...

The shallows as you put it - it depends what keel(s) draft you have ... I could cut quite a bit of the run into Langstone with my boat being bilge keels ... but would not advise anyone new to the area to follow !!