Other PicoMicroYacht

Tuesday, 16 August 2016

Puzzling Twin Peaks and Passing Old Harry in the Dark

I am getting to understand the tides a little better, but as you get more into tides they get more puzzling and mysterious.

The plan was to set off from Christchurch and voyage across Poole Bay to the Old Harry Rocks and then on to Swanage.


I would set off at 8.00 pm on Sunday 14th August and the tide would take me across Poole bay (starting at the bottom of the map).

The water enters Christchurch harbour via the 'run,' a narrow channel  through which vast quantities of water  must squeeze, impossible to go against in PicoMicroYacht. So I was expecting not to get out of the harbour until 8.00 pm when it was high tide. But when I arrived and set the boat up by 6.30, most of the water seemed to be in the harbour and I could set off.

Later I checked what  had happened and the tidal chart revealed three interesting but very puzzling phenomena.

Firstly, for each tide there is a mini 'stand' with twin peaks.  I have to admit I don't fully understand this mysterious double tide, but there is a description of what happens by Dr Ivan Haigh, a tidal expert from the University of Southampton, about 20 miles from Christchurch:

Apparently it is 'the combined effects of water sloshing across the Atlantic (a bit like in your bath) and spinning round because of the rotation of the Earth; this causes the water to slosh around a point which in fact is inland. When the tide ‘comes in’ water travels up along the coast but can’t navigate the corner into the North Sea and is reflected back down the coast.' He says it is not due to the proximal Isle of Wight. 


All I can recommend to understand this is sloshing water round the bath with a few objects in it; the sloshes might reveal that the height anywhere in the bath isn't a simple function of the water just moving along it and back.

Secondly, at neaps (not too much tide), the second peak is higher than the first, whilst at Springs (lots of tide), the second peak is lower than the first ... puzzling and I cannot find an explanation.

But I have just also noticed that every other twin peak high tide is larger ... even more puzzling.

So it there is anyone out there reading this who can explain any of this, please comment?

But I am not so exercised about the tides, and there are some things as a sailor you can just accept as fact; PicoMicroYacht took advantage of being able to exit a little earlier at 6.30 pm because the tide had stopped rushing in the entrance.

PicoMicroYacht was quickly out of the harbour. On a spit by the entrance I passed some of the most expensive beach huts one can imagine, a recent one selling for £260.00.00 - they have no toilets or washing facilities and shared shower block

As I traversed along the spit, a rich owner paddleboaded out to me to say hello and ask me about PicoMicroYacht.


Soon I was out into Poole Bay, looking back to see Hengistbury Head, on which are the remains of an iron age fort.


The sea was calm and I had been stemming the tide for over any hour until it turned in my favour. As the sun set and the sky darkened I looked across to Bournemouth.


It now now darkened quickly and I was across the bay approaching the Old Harry Rocks, looming out in the darkness. These chalk rock that sticks out into Poole Bay could be seen faintly in the moonlight but defied my photography. It is at this point you have look out for ships going pass Old Harry to go in and out of Poole Harbour, including high speed ferries.

As I was lining up to go past the rocks I spotted a light in the sky and a green navigation light more at sea level, just below it.


The white light was on the top of a tall mast and the green light was on the bow, indicating it was going to the right of me.  It was a large yacht motoring quite close to me as a I rowed to ensure I was out of the way, taking no risks. I could hear the crew talking to each other over the sound of their engine. I hoped they were looking ahead properly.

The yacht had distracted me and I looked round to see I was being swept through the race, a bit bumpy but not dangerous with no wind and a neap tide.

Soon I was in Swanage bay and looking for the sailing club to land, arriving just on midnight.

The next day the friendly bosun of the club chatted about boats as PicoMicroYacht  was taken from the beach.



Tuesday, 26 July 2016

A Pico crosses the channel again but this time without oars

PicoMicroYacht crossed the English Channel in 2012 but not as impressively as Dave Birch did recently, sailing his Pico dinghy from Guernsey to Torquay, a total of 73 miles in just over 14 hours in force 3 to 5 winds and with NO OARS.

He had a full sailing rig and was doing the dinghy sailing thing of hanging over the side deck getting very wet.

His epic voyage is captured in a short film.


PicoMicroYacht is currently inspired by his achievement and thinking of a new adventure.


Saturday, 2 July 2016

Knowing the tides aged 11 years

When I was eleven my best friend thought high tide was always at tea time.

He was right.

Whenever we went sailing on the coast, usually Chichester Harbour, our parents chose to go in the afternoon and selected sailing days for when there was a high tide. He didn't have to worry about the tides and just turned up for the sailing. The high tide transformed the estuary into a huge lake where you could go everywhere.

High Tide at Bosham, Chichester Harbour, where King Canute, King of Denmark, England and Norway, is reputed to have decreed that the tide should stop coming in, but was not successful on that occasion.



I was reminded of this when studying a Yachtmaster training book and reading about semi-diurnal tides, in which there are two high tides a day, separated by about 12.5 hours. I thought this was universal, apart from some local variations caused by geographical features such as Islands.

Image result for semi-diurnal tide

I was right .... well that is to say, around the British Isles, North West Europe and most of the East Coast of North America, not to mention other places in the world.

But I was to find out that I was thinking like my friend - as my son said today, I was right given the limitation on the data I had to hand .... but then I was to discover the tides are also di-urnal, with  one high tide a day, or even mixed, a sort of hybrid, as in the Pacific Coast of North America.

The semi-diurnal tides set the rhythm for the PicoMicroYacht voyages in the UK  because PMY always aims to go with the tidal direction when going round the coast, and this follows approximately the same periodicity.

High tide to low tide and vice versa is about six hours, and this is a typical limit for a PicoMicroYacht voyage. Assuming a 3.5 knot average speed, this provides a range of  about 21 nautical miles.   The recent 42 mile voyage round the southern Isle of Wight required two voyages in one day and, of course, eventually turning in the opposite direction up the Needles Channel changed the game.

Below is a heat map of tidal rates for tide in full flow up English Channel and past the Isle of Wight - it would be impossible to voyage against the red flow areas.
round the island, cowes




Thursday, 23 June 2016

Why is PicoMicroYacht so tough?


I was prompted to think about PicoMicroYacht's construction by some well-wisher asking me what would happen if it sprang a leak and sank - what would I do? Answer: radio the coastguard quickly get out my personal locator beacon, remembering to take some rations.

However, it turns out that PicoMicroYacht is constructed in a fashion that sinking is very unlikely.

It is made of roto-moulded tough plastic.


The Laser Pico is said to be thermo plastic tecrothene 100 rotmolded. Plastic is put into a mould and  and heated and whizzed around in the air, turned and flipped such that the plastic all sticks to the inside of the mould forming the hollow cavity of the boat. Through heating and cooling it sticks solidly in place. It is called 'roto' because the whizzing involves rotating in different directions.

But an ordinary process, such as making plastic petrol cans, would not make it stiff enough for a boat, so a foam core and another layer is added. I don't know how they do this as well, but they do.

Below is not the Pico, but the photo shows similar layering.

Image result for roto molding

The plastic process makes PicoMicoYacht incredibly tough, which why it can do things like be dragged across shingle beaches, dropped on the slipway and not need any maintenance. Also I am told that if it did spring a leak the foam core makes it unsinkable - but the Titanic was unsinkable so I am not relying on this thought too much.

Another very tough feature is the daggerboard - which seems to be solid steel reinforced fibreglass.




It doesn't snap in half -  as I have found on numerous occasions when I have grounded.

This could be a life saver - as this tale from PicoMicroYacht's hero, Jack de Crowe might illustrate:

Sandy Mackinnon

'Sandy' MacKinnon, an English and Drama teacher, and witty raconteur writer,  voyaged his Mirror dinghy, Jack de Crow, through the canals of England, down the Thames, across the English Channel and then across Europe to the Black Sea, all  in incredible good humour and lack of moaning about his difficult experiences. However, his most perilous experience was off the Isle of Sheppey in South East England when he smashed his daggerboard on a sandbank. With the strong tides and winds and inability to sail or row efficiently he was at risk of being swept out to sea with Jack De Crow being made into small bits of wood on the treacherous sandbanks off the North Kent coast. He saved the day by fashioning in situ a new daggerboard out spare wood he took on the journey and so lived to complete his voyage and write his wonderful book 'The Unlikely Voyage of Jack de Crow.'

You can't be too careful about daggerboards and PicoMicroYacht has a tough one.


97501




Sunday, 12 June 2016

Whats in a race?

It is sometimes hard to envisage going through a race in a small boat. What will it do to the boat? How big a race could PicoMicroYacht enter and get away with it?

In the various sea trips I have managed to avoid races altogether by going at slack tide or well out to sea.

A trick played by races is that a very calm sea can give you a false sense of security and lead you into the race, the tide accelerating; then you are committed.

These kayaks had a go through the St Catherine's race, where you can see it goes from smooth calm with a slight swell to a challenge in about 45 seconds.


They were experienced and knew what to do; after another two minutes the sea calms down comparatively. It would have been what a sailor calls a 'hairy moment' talked about in the pub afterwards.

A race often forms by headlands where the moving water is compressed, speeding up and causing rougher conditions.


This is exacerbated if there is a ledge, the rough water just after shallows.



If the turbulent water also encounters waves going in the opposite direction, the water is more likely to break, with short sharp waves collapsing.

Also, if two streams converge then this results in rough water as in the illustration of tides off the Hurst Point, entering the Solent. I avoided this by keeping close to the Isle of Wight.

However, the same things happens off the Needles and I had to go through the rough patch on that occasion, but with such a calm sea and the tides almost slack it was no problem until mainly through.



There is a great book called 'Coastal Turmoil' that explains it all, the above illustration taken from this book.








Monday, 30 May 2016

Completing the Voyage round the Isle of Wight



On 28th May the conditions were ideal for going round the south of the Isle of Wight and completing the journey, starting at Bembridge and finishing at Lymington, just beyond Yarmouth on the mainland. This would be a 40 mile trip in all, the longest by far for PicoMicroYacht.




Firstly I had to row round the eastern end of the Isle of Wight, not to be trifled with. The residual swell was breaking over the easternmost ledge, aptly named Sharpus rocks, exacerbated by the south going tide.


As I did this I looked back at the launching pier for the lifeboat, the lifeboat house on the pier very distinctive.


I then tracked southwards towards Shanklin and was about one and a half miles off Sandown when a large fishing boat paid a visit, a fisherman on the bow talking to me. "You need to get in, there's a force 5-6 coming in." There was a dark look of stern fear in his face. "You need to get in, not be out here."

This worried me, since the voyage hadn't really got going and I was stuck on the Island with a sudden high wind forecast. So I got out the computer, and plugged in my Oyster to check the forecasts again.

Apparently there was a deep low over the low countries which was causing high winds in the South East of the UK, but the inland and coastal forecasts were much more benign for my journey, force 2-3 knots, increasing 3-4 knots North East.

This was good enough to carry on since I was close to the shore and if the forecast was wrong and the low pressure started to have an influence further west, with the sea state slight I could quickly beach the boat. But that knowledge of a lurking deep pressure system stayed with me for the rest of the voyage.

I carried on steadily south until I reached Dunnose Point. This was one of my gateways, since it is known there can be a race there as bad as St Catherine's. But I was there almost at slack tide and saw no signs. The main hazards were lobster pots with long lines and trying to avoid these whilst keeping a look out for rocks on this coast.



Soon I was approaching Ventnor, where a small artificial port has been made for fishing boats.



I moored under the fishing plant and had a break, napping. I had a lucky escape from the fish processors who tipped their fishy water in a deluge onto the pontoon from the fishing plant above and missed me by about six feet.

I waited in Ventnor until the tide was getting slack again in order to pass by St Catherine's point, the most southern tip of the Isle of Wight. This is known to be suspect even in comparatively calm weather. As Peter Bruce writes in his book 'Wight Hazards' - "the race looks dramatic but is also dangerous.... the worst of the race can be avoided by working along the shore, but one should be prepared for nasty overfalls... from which there may be no escape.'

Just before St Catherine's is Wreeth Bay, when on a good day you can launch your dinghy. The sailors there were looking at me figuring out what kind of craft I was. Their laser in the foreground had just been out for a spin.



My strategy was to pass St Catherine's when the tide was changing and then it would push me westwards, ensuring a smoother passage, but the sea was still turbulent.


But soon I was round the point.




PicoMicroYacht was now on a long leg towards the Needles and I could look up at the cliffs and bluffs and see the comparative wildness of this part of the Island. Occasionally people could be seen walking the coast.


Every so often the sea would become less smooth as I passed a hidden ledge,  but the generally calm sea state meant this was not a problem.


Eventually I was in Freshwater Bay for a break whilst I waited for the tide to be slack for getting to the Needles and also checked the shipping forecast, which suggested light winds. Although there was a slipway, the residual swell meant it would be messy going ashore, so PicoMicroYacht stayed in the bay until the allotted time.




The next stage was the voyage to the Needles, at the Western tip of the island, a series of chalk rocks that jut out into the sea with a lighthouse at the end.

The idea was to reach the Needles when the eastern going channel tide was at an end so that on rounding the Needles it would then reverse and be helping PicoMicroYacht up the Needles Channel back into the Solent.

However, it is at this time the seas can be most problematic mainly because the water passing through the Needles Channel may have different vector from that going up and down the English Channel. But the wind was dropping all the time to nothing and the sea was very calm.

PicoMicoYacht moved sluggishly to the Needles, using up further time for the tide to change. It was getting darker and I took a short break in Scratchells Bay, just under the 1950s rocket testing base (I met recently someone who had been in this bay as a boy in the 1960s when suddenly and unexpectedly they had been enveloped in a dense mist with a shrieking sound as they tested a rocket above).

The Needles were there waiting, as the light was fading.


It was 10 pm and time to go. Given the fading light I was somewhat apprehensive but reasoned the sea was calm and there was no wind and it was a neap tide, the best possible conditions. It is possible to 'thread the Needles' (go in between the rocks) but not now I thought.

Going round the outside it is important to miss the Goose Rock and a wreck as shown in the photograph below from the 'Wight Hazards.'  The rock is just by the lighthouse and the wreck a little further out, the remains of the SS Varvassi's boilers, engine and stern, the ship a Greek cargo steamer that sunk there in 1947, apparently with all the crew and their cargo, tangerines, rescued.




The Varvassi regularly catches people out. This summer in the Round the Isle of Wight race the Alchemist went aground, drifted round into Scratchells Bay and sank. This fine old racing boat from the 1970s could not be saved in time by the lifeboat's pumps.

The Alchemist starting to sink ....



going...



gone...well almost..




I passed easily between the Goose Rock and the boiler, the rock appearing for me  at the bottom of each swell, flattish and the size of a garden trampoline, impressively gurgling.

The light was fading rapidly and as I looked back at the lighthouse it was becoming darker quite quickly.


PicoMicroYacht had done it! Now the stream was taking PicoMicroyacht up into the Solent. It was properly dark but a 'clear night' with all the navigation lights easily seen and I was confident people would also see me.  I rowed gently along the coast until I reached the Hurst Narrows, turned PicoMicroYacht by 90 degrees to head towards the mainland and let the stream vector take me into Lymington port. On the way I felt the sea roughen has I passed over the Fiddlers Race. It smoothed out as I looked for the series of navigation lights leading in to Lymington Harbour. It was just before midnight when PicoMicroyacht arrived at the Lymington Yacht Haven.

As I looked around for a berth a night watchman appeared  asking me my 'intentions' (not to break into one of the swanky motor yachts for the night,  of course - note: that was my joke, unspoken!). I explained the purpose of my journey and that our charity that had raised £18,000 and he told me that he would try to get my berthing fee waived, which he did. With no place to sleep, I had my emergency tent and was able to get four hours sleep aboard PicoMicroYacht.

Post-Script

I am grateful for the help from various people during the voyage. Mengeham Rythe Sailing Club recovered my voyage notebook, left on the quayside (although I had memorised the data, it had sentimental value; interesting reading because those who looked at the notes didn't realise the boat had been adapted for sea voyaging). I am grateful to Bembridge Sailing Club for letting me use their pontoon and giving weather advice, also allowing me to do so when they were very busy getting ready for a wedding. The kindly people from the Yarmouth Marina let me launch for free. The friendly staff from Lymington Yacht Haven allowed me to berth and also use their showers (incidentally the best marina ones on the South Coast).  Also PicoMicroYachts's occasional and patient helper Lorna (my wife) on my first trip collected me from Bembridge to take me back to Lymington. My thanks to the Solent coastguard who monitored the voyages using my AIS signal and the local coast watchers who peer at what is going on through their binoculars and telescopes and are the saving 'eyes' for our coastal safety. Ivor Reveley the organiser from CASPA made it all possible and I am so grateful to my generous charity sponsors for the voyage.


Voyage Planning

I set off at 5.30 am from Bembridge. Portsmouth high tide was 04.11 and this meant the tide stream was just turning to take me east out past the Bembridge ledges where a southerly tide would be in my favour for continuing onwards. The plan was to arrive at Dunnose Point at about 09.00 when the tide would be slack, to avoid the race. I would then go round the point and into the Ventnor port. The tide would now be against me, so I would take a long break in Ventnor (this included a full English Breakfast and napping) until about 15.00, which was about two hours before high tide at 16.59. I would use a back eddy (local reverse tide) along the shore to St Catherine's point, to time my arrive one hour before high time, when there should be slack water, again to avoid the race. I then would voyage to Freshwater Bay and kill time there so as to arrive at the Needles at 22.00, this being about five hours after high tide and a short period of comparatively slack water used to go round the Needles. An easterly going tide up the Needles channel would take me through the Hurst Narrows and onwards to Lymington. This last part of the journey took two hours, passing through the Hurst Narrows at about 23.00 by which time the tide would have accelerated to full velocity. I knew I could the 'ferry glide' (go one way and with the tide pushing me another way to go a third direction) across to Lymington. At his point the tide was the same speed as my rowing. All the timings worked out, although I got to just before the Needles about half an hour early and went into Scratchell's bay, to use up further time. The tidal considerations meant going round the Needles when it was getting dark and I had to be there with plenty of time to spare to get the timings exactly right. I was confident that there would be enough light left to be safe if I was careful. A plan B was to give the Needles a large berth and use my GPS system to navigated up the channel carefully, if I thought visibility was too low. Also if there was any sign weather deterioration I would turn round and finish at Freshwater Bay.

I found that going round the south side of the Island needed careful planning to deal with the various hazards, including four potential races and the danger of rocks scattered around the cost, also knowing that landing on the shore would not be possible without a calm sea - I was impressed by the number of dangerous rocks and hidden reefs. Imagine being pounded on one of these semi-submerged rock by the waves. I found particularly helpful for preparation a careful reading of Wight Hazards by Peter Bruce, now in the 4th Edition. The publicity describes it as providing 'detailed information .... such as transits to clear rock ledges and ariel photographs (allowing) small vessels to be navigated in confidence close to the shore.' The description of the Needles was particularly useful and I felt as if I had been there before when passing around the outer Needles in between the Goose  Rock and the Varvassi wreck.

I was also pleased that I had an AIS system. When the coastguard asked me for my MMSI number (call sign) I was able to point out that he could see it on his computer screen if he looked for PicoMicroYacht, which he duly did. Knowing the coastguard and my family could track my movements was reassuring. My son tracked my AIS position on his Android phone.




PicoMicroYacht voyages again to the Isle of Wight

The tides and the weather were just right to finish the voyage round the Isle of Wight. Light easterlies and calm seas were forecast. But first I had to get to the Isle of Wight and this time not using a ferry.


So I set off on Friday 27th June from my local sailing club, Mengeham Rythe, in Chichester Harbour.

The plan was to take the ebb tide out of the harbour. The westerly tidal stream would the sweep me into the Solent before reversing southwards, helping me down to Bembridge.


A Solo dinghy owner chatted to me from the club - as PicoMicroYacht was prepared.


It was just after high tide and I was ready to go, the tide ebbing out the harbour, and soon I was exiting the entrance, a strong tide was pushing me along.


A gaffer was silhouetted against the setting sun.




I  was now out into the Western Approaches to the Solent. The tricky bit is crossing the shipping lanes, which is done almost at 90 degrees (see middle of chart above), with large shipping  a hazard.

Fortunately the channel at this point is half a mile wide so can be crossed in ten minutes, a bit like sauntering across a road on foot.

A ferry crossed in front of me, conveniently early.



But you have to read the chart because just south of the channel is St Helens Road where the fast moving cross channel ferries deviate from the channel, cutting the corner, closer to the Isle of Wight. I was determined not to be caught out.

On cue, a Condor Ferry was passing through this short cut, but before I went across it.



Soon PicoMicroYacht was entering Bembridge



I found the mooring at the Bembridge Island Sailing Club. The Tom Tom Bandit set on time lapse photography shows the final trip into port.