... ... ... Seven years in an unassuming narrowboat on the waters of the "longest, friendliest village in England"  


Sharpness to Portishead in four hours on tickover

Posted on August 16, 2017 at 7:30 AM

The decision to slip Sharpness would be determined by the weather window. This presented itself at 8am on Sunday 13th August 2017 and was enabled by another narrowboat which had booked a passage (and a pilot) from Sharpness to Portishead marina. The narrowboat skipper had booked entry into the port of Sharpness via the low swing bridge which has to be booked 48hrs in advance. I followed him in (at 10.15am) while the gate was open and took my bollicking from the lock-keeper, (who said [rightly] that he had no prior knowledge of me or any booking). 

I told him I couldn't book the weather and had waited a week for a 'window of opportunity'. 

Following the other boat through Sharpness Dock returned memories of all the times I'd sailed out through Tilbury Docks on Kenya Jacaranda.

Pentargon tied longside and was let into the interim lock about 10.45. I noticed how tiny the lock was compared with the Panama specification of Tilbury and at the same time how tiny Pentargon was in relation to Sharpness Ship Lock .  The sea gate was open, the tide was flooding and would be for about another hour.  The lock-keeper made peace with me, maybe expecting to never hear from me again. The pilot told me what he would be doing and I told him I had a totally different plan. We wished each other bon voyage.  Because he had to race to make Portishead marina lock on a rapidly falling tide, he would shove off at 11oc and punch tide for an hour to get abeam Berkeley on the turn. As soon as he was in the ebb, such as it might be, he'd put the hammer down, following the flow and the marks and keep the power on all the way to the lock entrance at portishead.  I don't think he had any idea how much sea experience his listener had.  I kept my mouth shut and absorbed what I heard.  But, frankly, I was flabbergasted.  To punch even the last hour of tide from 11.15 to 12.15, a boat would have to use a lot of power.  The next hour (12.15 to 13.15) would provide precious little flow advantage so more power would be needed to make good way.   I am no longer surprised that so many boats which do this run with pilots need major engine surgery very soon after ...

My method would be entirely different.

"Pentargon" has about a usable 6BHP in her Lister engine and has never punched. She sails like the lighters of old, using the tide and  techniques learned from old Thames rovermen and honed over many passages of the Thames Estuary between 2015 and 2017.  My Bristol Channel charts showed I should lay a southerly course towards Berkeley Power Station four miles away, before turning west at a cardinal and dog-legging to the other side. I had researched as much as I could but found no published information anywhere on how to go with the flow in an almost powerless narrowboat ... I would have to figure how the old guys might have done it.

During the lie over I had met the Sharpness Coastguard and even they did not know.  But they were able to show me some right lurid photos of boats that did NOT make it.  That evening I re-checked my anchor and its lines and shackles, laid everything out for instant deployment, checked my safety harness and the safety cables running the length of the roof  ... and inspected my Helley Hansen and lifejacket  ...

It was already decided that Pentargon should break away from Sharpness pier just after the turn of tide.  Lockie had told me he needed the sea gate closed by 12oc and this meant my boat had to be OUTSIDE before then. At 11.50, I eased Pentargon out the sea gate to tie up on the pier outside and tide-wait.  I would be waiting for the turn, and seeit turned, before I would let go. The next 20 minutes was spent "watching seagulls" and gradually easing the boat further out along the pier. There was a slight SW breeze, "wind over tide"; the sky was slightly overcast but blue, visibility was excallent.

It was a nice day to go to sea ...

At 12.15, I noticed Pentargon straining on her lines. The ebb was just starting and water was coming under the pier to push the boat off, ever so gently.  Seagulls further out confirmed we had top of tide so lines were slipped. The boat fell away gently from the pier.  With the engine on a healthy tickover, gearbox was engaged and there was now no turning back.  I had launched into the most dangerous and unpredictable water in Britain trusting entirely on a lifetime's sea experience, a clean fuel tank and an engine that had never let me down. 

Berkeley Power Station makes a fine point of reference in the first hour and I drifted along on whatever current there was.  The Channel is so huge it is difficult to establish and maintain transits but looking back every five minutes Sharpness was definitely moving away from the boat as it were.  Pentargon would be doing about 2kts over water plus whatever tide she might pick up on the ebb. After ninety minutes we were abeam Berkeley. I was looking for a cardinal mark which would indicate a solid right turn to head right across the estuary towards the western shore.

But the currents were favourable and were going with us.  Briskly!  By the end of the second hour out we were at the other side of the Bristol Channel using transit marks and it was time to push the rudder hard to starboard for the third tack ... under the M4 and with the bow pointing at the eastern end of  the M48 road bridge.  We were entering the Shoots, some of the fastest flowing seawater in Britain, possibly flowing at almost 15mph. No body knows the water speed in the Shoots in the third hour

The crabbing attitude was necessary to counter what was now a very strong current in The Shoots and I was aligning the boat to eventually go sideways through the centre span of the M48 with the nose pointing at the distant Avonmouth port clearly visible on the horizon under the M48 span about ten miles away. We had marks to follow and avoid!  It took an hour to haul up off Avonmouth and NW of the Kings Road but we were quite a way off the shore.

So the boat was pointed strongly towards Avonport to get us in as close as possible to shore and inside Kings Road.  It would be very easy to be swept past Portishead ... in the 4th hour of tide. Cornwall was not in the day'd plans. A nice overnight anchorage outside Portishead marina would do nicely. But we needed to fetch it

By persistently pointed Pentargon's nose at the mouth of the Avon initially and then at Portishead Seawall, the outflow of the river was partly neutralised but it was quite obviously there.  I eventually ended up with the boat actually pointing upstream inside The Kings Road and beyond Portishead seawall.  But the current was very low probably about one knot so it was easy to motor slowly northwards til it was feasible to turn the nose to shore and motor on til the boat grounded in the mud.

Although this sounds a bit stupid, it is a good idea and a right lazy way which is known to sailors, watermen and lightermen.  If you plough into the shore when the tide is falling, you will stop and once and there will be no more movement til the tide goes right out and then back to the point at which you went aground.  Pitching an anchor overboard as insurance means you can go for a sleep during the interim and be ready for further action next time the tide floats yo boat ...

Tide is falling away.  Boat's going nowhere.  We're not an obstruction.  There is no water for boats to sail in. Hours later the incoming tide will lift her off and we can park up properly off the fairway.  For the first time since we slipped Sharpness at 12.15 we can totally relax.  A call to the marina master on VHF to explain was aground in his fairway and why was in order.  He told me traffic would be entering that evening from about 8pm and asked whether I was going in.(Google "Portishead The Hole" for some beautiful pictures by Hillary Hinton of my overnight stop)

I assured him I would move in before that to totally clear the fairway but would be anchoring outside overnight to take the morning tide to Bristol.

I had a shouting chat with the skipper of the narrowboat mentioned earlier. He was safely in and staying there for a couple of days. I stayed mum at the amount of 'hard-earned' he would have leaked. £200 for the pilot Sharpness to Portishead. About £80 a day for his boat in the marina. £100 for a pilot to Bristol. And the scruffy little Springer lying in the mud about 40' below his eyrie on the sea wall was doing a freebie and save the price of her 2019 licence.

Time to get dinner on and have a siesta or vice-versa. But it was a total relax for a few hours, then when she next floated move her into the creek a bit and sling an anchor. I did sling the mud-weight but it was more for practice than anything else. The boat was going nowhere.  

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