weather & tides

From Steeple Point – waves (cont.)

/ Bill / 3 Comments

The previous afternoon the weather was similar. . .

a light swell is coming off the Atlantic.

Waves are in motion, just visible, moving towards us across the surface of the water – at speed.

The actual water they pass through is barely changing position, describing small, slow, circular, vertical orbits.

Finally, almost at the last moment, a small section of a wave is cut off  by the rocks-  guided into a gully.

Forced into the tight space, it loses speed as it drags against the sides. But it retains its energy.

Thus gaining height, it trips over itself, breaking on some underwater obstruction.

And now it is the water itself  – (at a ton per cubic metre), that is surfing down the face of the wave, accelerating towards us.

In speeding up, it quickly reaches its end, dashing itself with abandon on the Breakwater – while, a few seconds later, the rest of the wave, still in the freedom of comparatively open water only a few feet away, rolls sedately up the stones.

And here, it is lifted by the swell above the surrounding sea, only to sluice downhill across the rocks, seeking balance with the main body of water.

On sailing a Folksong – just checking

/ Bill / 1 Comment

This post is for fellow Folksong owners – knowing you would understand.

On the way to St Ives, we detoured to check on the boat.

Around 1230, it was raining hard – big drops with more to come.

All seemed secure, so we drove on – south west, meeting the heavy weather on the road, half of me wondering how things were on the mooring now.

From Steeple Point – waves

/ Bill / 3 Comments

Last Saturday, browsing through my favourite second-hand bookshop – Books by the Sea in Bude, I found a book on seamanship by John Russell – The Shell Book of Seamanship, published in 1974.

I already have another book of his – Yachtmaster Offshore, published in 1977 for the RYA  Seamanship Foundation and bought around that time.

Note the publishing dates – before a lot of things that have happened since.

I like his attitude.

From the blurb inside the dust cover: ” . . . ‘safety equipment’ is a misnomer. It is emergency or survival equipment. True safety comes from good seamanship which minimises the incidence of accidents and that is what this book is all about. Examples of true safety equipment . . . are the humble electric fuse, the lifeline and the harness . . . and the pound or two of slush that every one of us carries around for life in his skull.”

It is the slush, of course, that is the problem.

~~~

Chapter 3 is entitled ‘The Sea’ and deals with waves.

Coincidentally, my photos of the weekend included waves and I have put some together with John Russell’s text to see how they fit.

The weather was governed by high pressure.

The sky was blue, with occasional light cloud.

Such wind that there was was north westerly as the Cornish flag on Chapel Rock shows.

The sea was flat – you would not expect any waves other than the residual swell from weather far out in the Atlantic.

And this is what we had – the chance to look at individual waves washing ashore.

~~~

“When the wind stops blowing or changes direction, the sea it caused continues to travel on as a swell . . . Without the energy of the wind to sustain them the waves of a swell gradually decrease in height, but their period and length continue to increase, although at a diminishing rate: thus they become less obvious but move faster as they travel away from the original area.”

“. . . When the wave enters water less deep than half the wave length it begins to feel the interference of the sea bed. Its length decreases without alteration in its period, so it goes more slowly, while its height, after an initial slight decrease, begins to increase rapidly with decreasing depth. This causes the swell to become shorter and steeper . . .”

“When the depth of water falls to one-tenth of the deep-water wave length the increase in height becomes very marked, the progressive deceleration causes crowding with steepening and narrowing of the crests, retardation of the troughs steepens the wave fronts more than their backs and the wave is ready to break at the least provocation. At a depth equal to one-twenty-fifth of the deep-water wave length the relationship between length and period disappears, the wave speed becomes dependent on depth alone and it breaks.”

“For a given speed the energy of a breaking wave depends on how much solid water, as opposed to air and water, it contains, but with sea water at a ton a cubic metre even a modest, well-aerated crest produces  a clout equivalent to collision with a small car.”

“It seldom happens that the fronts of advancing waves are parallel to the bottom contours, so one side reaches the critical depth and begins to slow down before the rest with a result similar to optical refraction. Refraction causes the swells to swing round and align themselves with the bottom contours.”

“Waves frequently cross and even when they travel in the same direction their different characteristics blend to give results that do not appear in either system alone. When the difference in length is pronounced, as commonly occurs when  a sea is meeting or being overtaken by an old swell, the two component waves retain their identities. But when waves of only slightly different period and length combine they produce groups of noticeably higher waves interspersed at intervals with groups of remarkably lower ones as the component waves move in and out of phase,”

~~~

It is worth concentrating on the extracts above. Even if not written in customary blog language, they are a very good description of an often ill-described phenomenon.

You might ask why a book on seamanship should include a section on waves. Well . . . that’s where the ‘slush’ comes in.

“

On sailing a Folksong – spinnaker preparation

/ Bill / 2 Comments

I went aboard during the slack tide to do a few jobs – strengthen the mooring lines, make it easier to drop the pick-up line and also the anti-chafe plastic piping on the stern lines had slipped and need re-securing. I ran the engine and remembered how much it needs a service.  And there was very little water in the boat – one pull on the hand-pump was enough.

~~~

When I bought Blue Mistress, I inherited a spinnaker that had seen better days and, having written it off, I have been content to sail without one. However, I have recently acquired a nearly-new spinnaker from a Folkboat –  (North Sails), so am now looking at ways of setting it.

The idea is to prepare the ground for doing it single-handed and then, for the first few times have a crew, to test out the the theory.

By sewing tags onto the spinnaker bag at the forward ‘angles’, I can tie it to either side of the pushpit forward of the stanchions. It will be held open by the line to the forestay and fixed at the base to the bow roller. The bungee cord can be tightened or loosened to control the size of the opening and keep the sail in the bag until needed.

Having worked that out and found the halyard was not long enough to feed back to the cockpit, which could be a problem –  (and dropped the bag back into the dinghy to bring home for sewing), I looked at the pole.

I wanted to decide on lengths – length of sheet/guy and downhaul.

By shackling a block forward, and feeding the downhaul back to the cockpit, I can control it from there.

The sheet/guy can be fed to the second track aft of the main sheet track and brought round the winch to the usual cleat, (Blue Mistress does not have self-tailing winches – doesn’t seem to need them).

I know it’s possible to do this single-handed because it happens on Fram.

In theory, given a good day and light winds, I could probably manage this sail – but, hey, that’s theory and I have a way to go yet. (All suggestions gratefully received).

~~~

By the time I came to leave, the flood tide was well under way and it carried the dinghy back to the slipway.

Just the two of us on this trot at the end of February – Blue Mistress and Charisma.

South Devon sunrise

/ Bill / 1 Comment

There are a few occasions in the year when my journey to work coincides with sunrise.

from Labrador Bay, 1st December 2009

These are the ships I mentioned in a post from Southwold last September – still there, still waiting for trade.

I have learnt more about them since, in particular the concern they have created in some quarters – here.

~~~

Fifteen minutes later, five miles further on, the sun higher, the perspective lower, the same ships . . .

from Meadfoot Beach, 1st December 2009

On Sailing a Folksong – annual mooring lift

/ Bill

The row out to the boat was shrouded in the morning mist – the top of the tide increasing the deep silence over still water.

Others were busy too. It was the annual mooring shift to allow the Cattewater Harbour Commission to lift and reset the moorings – a valuable service that gives peace of mind but requires some swift work to oblige.

The buoys are stripped of their usual tangle of lines and shackles, most of which have been there all year. As a result the pins are usually well and truly fast.

In Blue Mistress’ case this is not altogether true. We lost a pin due to a poorly moused shackle earlier last autumn, so there is one new, easily removed shackle. In fact all three of the shackles on our stern buoy (above) were relatively easy to remove but the two on the bow buoy were jammed. It required a very large spanner, another one jammed in the shackle to hold it still and two of us to lean on it.  Thanks to Freya’s skipper for his foresight and help – I promise to buy a bigger spanner next time!

~~~

When I looked up the fog had lifted and the rowers were out.

It seemed to good an opportunity to miss, so I motored down to the end of Mountbatten Pier in the sunshine, catching “Sweet As” returning from an early morning fishing trip.

The emphasis then came on lorries parked for the weekend – here below the mark (DirFRWG),

and here in gentle salute on the Cattewater Wharf.

On sailing a Folksong – Sunday morning log

/ Bill / 1 Comment

I was expected in Exeter this afternoon but checking the boat after the snow, the frosts and the rain of the past two weeks was a priority, so I seized the moment this morning.

The drive to Plymouth is about an hour and I got there about 10:15. By the time I had pumped up the dinghy, talked to the man who was going fishing in his ocean kayak and taken some photos, it was about 10:45 when I finally arrived aboard.

There is debris in the river from the heavy weather. In general, it floats past, but occasionally snags boats that are moored on the trots.

The mooring lines were as I had left them two weeks ago. There were no loose halyards. The sail cover was still firmly in place – it is too short and I have promised myself I will get one the right length one day. In the meantime, the boom end is covered by a square of canvas.

She looked neat in the morning sun.

The ten minute row demanded a small celebration.

Then start the engine (it fired first time!) and a look around before getting on with the several jobs I had planned:

The seagulls were enjoying the sunshine;

the fine house on the Cattewater shore was still overwhelmed by her industrial neighbours;

the boatyard on the opposite shore was the usual marvellous jumble of work-in-progress;

and the rowers were taking advantage of the weather.

A good day for a sail. Pity I had to return so soon.

On the Ceres – 73 years ago today – not forgotten

/ Bill / 1 Comment

Ceres 1811 – 1936

As I write, I can hear the wind hammering the trees in front of the house.

The inshore waters forecast for here gives southwesterly 6 to gale 8.

For the Bristol Channel it gives:

Lands End to St Davids Head including the Bristol Channel

The outlook for the 24 hours following 1200 Tuesday 24th November

Strong winds are forecast

Wind: Southwesterly 6 to gale 8, increasing severe gale 9 at times, perhaps storm 10 later in west

Sea state: Rough or very rough, occasionally high in west

Weather: Squally showers.

Visibility: Moderate or good, occasionally poor in west.

I mention this because 73 years ago today, off Baggy Point on the north coast of Devon at the western end of the Bristol Channel, on a quieter, fog-ridden day, the Ceres foundered.

The report in the Bideford Weekly Gazette on 1st December 1936 is recorded below.

~~~

The following year, my grandfather commissioned Pelham Jones to commemorate her on canvas (above). The painting is a wonderfully optimistic depiction of a coasting ketch, albeit with her competition lurking in the background. It is a painting for her owner to enjoy.

I find John Chancellor’s painting of the Ceres to be equally optimistic. I suspect he painted her purely because he enjoyed painting ships and boats. This is a painting for the artist himself to enjoy.

Taking Bude After a Blow, by John Chancellor

~~~

Taken from an article in the Bideford Weekly Gazette dated December 1st.1936.

“FATE OF THE “CERES”

The 125 years old “Ceres”, veteran of the merchant service, her course now run, lies at the bottom of Bideford Bay, somewhere off Baggy Point.

The “Ceres” sprang a leak on Tuesday night while on a voyage from South Wales to Bude, and foundered after her crew had put off in her boat and had been picked up by the Appledore lifeboat. The Captain is Mr Oswald Jeffery, a married man, whose home is in Richmond Road, Appledore, and the mate Mr Walter Ford, a married man of Irsha Street,, Appledore. They reached Appledore in the lifeboat at about 11 o’clock, and on arrival the Rev Muller offered a short prayer of thanksgiving for their safety.

Captain Jeffery said,” We left Swansea on Tuesday bound for Bude with a cargo of slag. Because of the weather we intended to go in over the Bar for the night as it was to rough to venture on to Bude. At 8 o’clock I went below to rest for an hour, leaving the mate in charge. An hour later he told me there was water in the engine room. We manned the pumps. We tried to get the ship over the Bar, but the water made her roll badly, and I gave the order for the ship’s rowing boat to be launched. I fired two rockets, and we abandoned the vessel. We lay in the shelter of the “Ceres” which was sinking, and were taken onboard the lifeboat.

Dr. Valentine stood by in case medical assistance was needed, but although wet through, neither the captain nor his mate appeared any the worse for this ordeal.

The “Ceres” was owed by a Bude firm of coal merchants, and was built in Salcombe.

Ketch Ceres 1811 – 1936.

Built in Salcombe, Devon in 1811.She carried stores as a revitaling ship at the blockade of Brest during the Napoleonic wars. Was the oldest sea-going vessel afloat until she sank in Croyde Bay one November evening in 1936. My late father Walter Ford always maintained that she sank because the vessel had recently had a new timber set in, and this had swollen and had displaced the much older timbers which surrounded it.

The night she sank was flat calm and the sky clear.”

For further posts on the Ceres here.