London Cruise - The Cunning Plan

This may only be a one week trip but it's been much anticipated and carries high hopes of a high old time (or to put it another way, Jane is really looking forward to this one!)

However, it's been on, off and then on again in the advance planning stages, we thought we'd have a crew of four however due to domestic upheavals now there'll just be the two of us and to cap it all the weather forecast has not looked at all promising for a few days

The problem is tropical storm / hurricane (it did briefly make it to Category 1 status) Bertha which has been following the tyical track North up the East Coast of the USA and which is expected to become a weaker extra-tropical storm and cross the Atlantic to Europe

The tail end of Bertha will likely bring heavy rain, strong winds and isolated gales to somewhere but the question is where because the various models can't even agree with themselves exactly where ex-Bertha will make landfall ...

This graphic shows the various predicted tracks of low pressure areas and the low associated with Bertha can clearly be seen following a fairly typical route across the North Atlantic

But will it arrive over the Channel? The Midlands? Or will Ireland and Scotland cop its full fury?

It might even go and give the French a good soaking!

And wherever it ends up, there's a great deal of uncertainty about just how deep the low will be

Taking a look at the jetstream forecast for Saturday morning it does look to me like an Atlantic weather system would be carried South of Ireland and then stomp all over the UK from South to North

And the shape of the forecast jetstream (unsurprisingly) looks much like the shape of the forecast track of the remnants of Bertha

OK, so it looks pretty certain that we'll have a low pressure system tracking through over the weekend. Let's look at specifics ...



Looking at the Surface Level Pressure forecast for Saturday morning, we have a moderate low (1000) centered over the North East coast of England.

As the day wears on, this low moves gradually North and maintains a steady pressure.

We can see the Azores High to the South West (bottom left!) which is trying to push in but the jet stream is keeping it at bay





You can see the low moving away to the North and the high pressure trying to build in over the West coast of France

So what does this mean for the weather?

Well that's the tough one to answer. These predictions are still, just 72 hours or so out, comimg with a low confidence rating (60% or thereabouts) which means the models aren't totally in agreement and the forecasters can't make their minds up!

We can live with rain so all we really care about is the wind ...

So here's the GFS (one of the various weather models) forecast for wind at 09:00UTC on Saturday morning or in other words about the time we'll be bashing our way into the Medway. The 03:00 and 06:00 wind forecasts are roughly similar. This would suggest we're looking at Westerly or South Westerly F4/5 which would be lively but good sailing.

That, compared to the gusts up to F9 that were forecast for Saturday a day or two ago, puts us on a go for the first leg. A quick check on Monday's weather ...


... suggests from the SLP synoptic that things should have calmed down although there's some interesting low and high pressure ridge systems fighting for supremacy over the UK and Europe

That might bring some brisk conditions across the Southern North Sea ...

However, as we'll be heading upriver on Monday it shoud be OK

So enough of the weather, what about the plan?

All things being equal, Jane and I will drive down straight from work on Friday morning and dinghy out to Erbas without bothering to come alongside.

We'll either drop downriver straight away or more likely grab a few hours sleep and do so late afternoon. My inclination would be to drop anchor in the Brankfleet but we'll liase with our friends aboard Laurin on that, I think there was some talk of picking up a buoy for the night to avoid having to exit Burnham Yacht Harbour in the dark.

And it will be pretty dark when we get under way on Saturday morning.

So here's our route from the anchorage in the mouth of the River Roach to Chatham Maritime Marina

As you can see, we have to head East North East for several miles to clear the shallow drying sands of Foulness and sneaking across will not be an option as we'll be rounding the Whitaker Beacon, which marks the end of the sands, at close to low water. Oh and it's also one of the most active and top secret firing ranges in the UK and they tend to get a bit miffed if you stray into the danger area (ahem!)

Once round the Whitaker, we turn South West and head down the Swin along the edge of the Maplin Sands, firing range all the way, before carefully crossing the shipping lane into the Thames in an area known as The Warp. Then we head for the Medway through The Nore, which as readers of nautical books will know is a famous anchorage, and avoiding the wreck of the SS Richard Montgomery which failed to anchor properly in The Nore and was wrecked just outside the shipping channel and still contains enough explosives to make a very large bang indeed

Into the Medway then and past various shipping terminals and loading piers we reach Chatham Maritime Marina, in the former naval docks, and lock in for a well earned rest

This is one of those trips where catching the tide is really critical to a good passage. Make the turn around the Whitaker Beacon somewhere close to low water, having used the last of the ebb to get a bit of a lift out of the Crouch and down the Whitaker Channel, and we pick up a fair tide on the flood all the way down the Swin and into the Medway

Leaving at 03:00UTC (four in the morning in body clock time) and we make the passage in under 8 hours at our best economic speed under motor of 4.5knots. Of course, we would hope to be sailing it but that's going to very much depend on whether the wind gives us an angle or not. I doubt I will be minded to spend the whole day tacking backwards and forwards between the Maplin Sands and The Barrow on the back of two bouts of a few hours sleep in the previous 36 hours!

On that basis, we'll be tied up and putting our feet up in Chatham by lunchtime which will suit me just fine. In contrast, delaying our departure by just two hours to an entirely more sociable six in the morning would add three or four hours to the passage time and we'd be lucky to make it to Chatham by six in the evening. Better, then, an early start and an early finish. We'll just have to make sure there's plenty of coffee on board!

We'll be spending Sunday in Chatham and then departing Monday morning for London. That too will need to be an early-ish start as once again carrrying a fair tide up the Thames is essential and we only have two hours either side of High Water at London Bridge to get into St. Katherines Dock

St. Katherines Dock, Tower Bridge and the Tower of London

Weather permitting we'll be staying in St. Kats until Friday morning, then sailing back down the Thames to either Queenborough or to anchor in the lower reaches of the Medway

Saturday will hopefully see us back in our home river and we'll be heading for the bricks and mortar either Sunday or first thing Monday morning