Below is part of a bigger story concerning how Pentargon took it's skipper on a circuit of England from Dartford to Dartford by Dudley and Devizes which eventually resulted in the longest solo circuit ever achieved by any type of narrowboat on
inland waterways as defined.
Portishead to Bristol on Tides
Posted. At Bath. Aug 16, 2017 7:35 AM
Has anyone actually EVER done a solo transit from Sharpness to Bristol? ALL the published information from all available sources is totally off the wall and entirely useless for 'novice' or fool. I decided to read all about it and then do it my own way as I would if I were going to Dartford.
Yesterday (Sat Aug12) Pentargon took me down from Sharpness to a safe anchorage outside Portishead. Now, I want to get from here to Bristol Floating Harbour, using tide, a ListerSR2 engine and a 1973 Springer.
Overnight the tide rose 12m. At top of tide some large ships came up the Channel and into Avonmouth under tug control.
On full tide, Pentargon bobbed a bit from the wash generated by those ships well out in the Kings Road maybe two miles away.
Pentargon was lying behind a mudbank, not quite as high as the actual tide itself.
(Google Portishead Hole!) I slept well, rocked by the hypnotic movement.
About 8am on Sunday morning, anchored outside Portishead and with the tide into its second hour, Pentargon was well afloat.
Avonmouth low had been at 6.20 so there should be a tidal flow to position the boat alongside Avonmouth's sea wall If one were to slip anchor and get out into the tide.
Pentargon would probably flow up to the Avon, two miles away, in less than an hour.
In the event she was by the wall at 8.30am. 2kts of tide added to 2kts of screw. 4kts!
... and if she turned into the Avon, avoiding the river's outfall, she should find tide along the wall and use it to get to Bristol.
I'd have to watch the rippling interface between the tide and the river like a hawk.
Stray across that shear-line and the boat would turn on sixpence and take the river downstream. Here's where detailed study of the Darent's streams in 2015 took on special significance. I was able to read the water surface and the currents, observe where the shearline was and stay tideside.
The same skill works for any creek flowing real water. Pentargon is used to doing those. She could do it with her eyes shut, so long as the skipper kept his open.
We'd honed this skill together to get off the Thames and into Bow Creek many times. It worked well for the Roding at Barking also and for getting into the Darent.
But they're only baby rivers: the Avon is real. My safety harness was clipped to it's eye and I should have been shittin myself.
Great fun at the mouth, as you have to make sure you avoid the river downflow by keeping the boat in the tide close into the wall. Later when the tide climbs over the river, man overboard would be fatal as the undertow would take a body to the bottom and keep it there. But I was alone and I was clipped to the boat. Once the tide got on top we went up like a surfboard on a slick of seawater no more than 2ft deep and over a freshwater river of undetermined depth.
For all and any armchair sailors it's essential to read the water at the mouth of any high flowing river. The Avon is more interesting than the rather placid tributaries of the Thames. REAL water-watching is called for.
9oc came and went and so did many startled seabirds. We zoomed under the motorway bridge, now firmly established in the stunningly beautiful gorge, the tide working with us and we working with it. Pentargon shot up the Avon and under Brunel's suspension bridge.
My only regret at solo sailing is that I can't use a camera in 'dangerous' or testing conditions. Take my word for it; Brunel's extra-ordinary masterpiece passes swiftly and very high above.
Over six miles from Avonmouth to the lock and we were longside in ninety minutes, demonstrating how the incredible Channel tide bundled us ceremoniously up the gorge. This is the Bristol Channel doing things more energetically than the sluggish Thames Estuary or the noble Shannon. Up by the lock at 10oc then and again charts and information were useless.
A holding pier shown on the 'Bristol Pilot' fell apart years ago. The whole place is covered in very greasy mud. But I made fast and managed to get ashore to see the lie of the land. Carrying my VHF, I was able to talk with the harbourmaster.
Coolest dude on his part of the planet had seen everything in his time including, no doubt a decrepit Springer, tied up outside requesting entry. A laconic response that he would be releasing some trip boats soon and, if I did not mind hanging about awhile, he'd sneak me in after their departure.
I slobbered back to my boat, over the slimy mudcovered hinterland. One slip here and I was a goner, but discretion prevailed.
With my boat still secured to a remnant of old decency, a cuppa rosie was brewed, more from boredom than necessity.
I let go about 10.30, again more out of boredom than necessity, made up to the lock gates for a look and then pottered around as the river filled. Up here inflow is minimal. The level just rises imperceptibly. Its ability to flow inland is restricted by the topography so the only way is up.
The trip boats came out about 11oc and I motored into the lock and threw a line to the nice man who threaded it through a steel ring on the end of a long chain and dropped the bitter end back to the boat.
The lift would be about 25 feet even in the fourth hour of tide. Down at Avonmouth, predicted high was 11.9m at 12.20z.
By then I'd be long gone ...
The harbourmaster promised to fill the lock slowly, but exhorted me to control the boat by hauling in my rope as we rose.
I was fascinated to discover the chain and ring were wound in by a donkey engine as the boat went up. About 11.15 I got first sight of Bristol Floating Dock. ... Back on 'terra firma' (in a manner of speaking), the Bristol channel was now just a memory.
'They' said it couldn't be done ... and it turned out to be so much easier than the first time I'd attempted Dartford Creek.
Gloucester to Bristol via Portishead had been transitted as easily as we had done Bow to Dartford via Greenhithe.
Hindsight and previous experience make great bedfellows.
Don't try this without doing as much homework as I did
inland waterways as defined.
Portishead to Bristol on Tides
Posted. At Bath. Aug 16, 2017 7:35 AM
Has anyone actually EVER done a solo transit from Sharpness to Bristol? ALL the published information from all available sources is totally off the wall and entirely useless for 'novice' or fool. I decided to read all about it and then do it my own way as I would if I were going to Dartford.
Yesterday (Sat Aug12) Pentargon took me down from Sharpness to a safe anchorage outside Portishead. Now, I want to get from here to Bristol Floating Harbour, using tide, a ListerSR2 engine and a 1973 Springer.
Overnight the tide rose 12m. At top of tide some large ships came up the Channel and into Avonmouth under tug control.
On full tide, Pentargon bobbed a bit from the wash generated by those ships well out in the Kings Road maybe two miles away.
Pentargon was lying behind a mudbank, not quite as high as the actual tide itself.
(Google Portishead Hole!) I slept well, rocked by the hypnotic movement.
About 8am on Sunday morning, anchored outside Portishead and with the tide into its second hour, Pentargon was well afloat.
Avonmouth low had been at 6.20 so there should be a tidal flow to position the boat alongside Avonmouth's sea wall If one were to slip anchor and get out into the tide.
Pentargon would probably flow up to the Avon, two miles away, in less than an hour.
In the event she was by the wall at 8.30am. 2kts of tide added to 2kts of screw. 4kts!
... and if she turned into the Avon, avoiding the river's outfall, she should find tide along the wall and use it to get to Bristol.
I'd have to watch the rippling interface between the tide and the river like a hawk.
Stray across that shear-line and the boat would turn on sixpence and take the river downstream. Here's where detailed study of the Darent's streams in 2015 took on special significance. I was able to read the water surface and the currents, observe where the shearline was and stay tideside.
The same skill works for any creek flowing real water. Pentargon is used to doing those. She could do it with her eyes shut, so long as the skipper kept his open.
We'd honed this skill together to get off the Thames and into Bow Creek many times. It worked well for the Roding at Barking also and for getting into the Darent.
But they're only baby rivers: the Avon is real. My safety harness was clipped to it's eye and I should have been shittin myself.
Great fun at the mouth, as you have to make sure you avoid the river downflow by keeping the boat in the tide close into the wall. Later when the tide climbs over the river, man overboard would be fatal as the undertow would take a body to the bottom and keep it there. But I was alone and I was clipped to the boat. Once the tide got on top we went up like a surfboard on a slick of seawater no more than 2ft deep and over a freshwater river of undetermined depth.
For all and any armchair sailors it's essential to read the water at the mouth of any high flowing river. The Avon is more interesting than the rather placid tributaries of the Thames. REAL water-watching is called for.
9oc came and went and so did many startled seabirds. We zoomed under the motorway bridge, now firmly established in the stunningly beautiful gorge, the tide working with us and we working with it. Pentargon shot up the Avon and under Brunel's suspension bridge.
My only regret at solo sailing is that I can't use a camera in 'dangerous' or testing conditions. Take my word for it; Brunel's extra-ordinary masterpiece passes swiftly and very high above.
Over six miles from Avonmouth to the lock and we were longside in ninety minutes, demonstrating how the incredible Channel tide bundled us ceremoniously up the gorge. This is the Bristol Channel doing things more energetically than the sluggish Thames Estuary or the noble Shannon. Up by the lock at 10oc then and again charts and information were useless.
A holding pier shown on the 'Bristol Pilot' fell apart years ago. The whole place is covered in very greasy mud. But I made fast and managed to get ashore to see the lie of the land. Carrying my VHF, I was able to talk with the harbourmaster.
Coolest dude on his part of the planet had seen everything in his time including, no doubt a decrepit Springer, tied up outside requesting entry. A laconic response that he would be releasing some trip boats soon and, if I did not mind hanging about awhile, he'd sneak me in after their departure.
I slobbered back to my boat, over the slimy mudcovered hinterland. One slip here and I was a goner, but discretion prevailed.
With my boat still secured to a remnant of old decency, a cuppa rosie was brewed, more from boredom than necessity.
I let go about 10.30, again more out of boredom than necessity, made up to the lock gates for a look and then pottered around as the river filled. Up here inflow is minimal. The level just rises imperceptibly. Its ability to flow inland is restricted by the topography so the only way is up.
The trip boats came out about 11oc and I motored into the lock and threw a line to the nice man who threaded it through a steel ring on the end of a long chain and dropped the bitter end back to the boat.
The lift would be about 25 feet even in the fourth hour of tide. Down at Avonmouth, predicted high was 11.9m at 12.20z.
By then I'd be long gone ...
The harbourmaster promised to fill the lock slowly, but exhorted me to control the boat by hauling in my rope as we rose.
I was fascinated to discover the chain and ring were wound in by a donkey engine as the boat went up. About 11.15 I got first sight of Bristol Floating Dock. ... Back on 'terra firma' (in a manner of speaking), the Bristol channel was now just a memory.
'They' said it couldn't be done ... and it turned out to be so much easier than the first time I'd attempted Dartford Creek.
Gloucester to Bristol via Portishead had been transitted as easily as we had done Bow to Dartford via Greenhithe.
Hindsight and previous experience make great bedfellows.
Don't try this without doing as much homework as I did
